@article {1062, title = {Characterizing ionospheric variability through HF Doppler measurements: a statistical and numerical ray tracing analysis}, journal = {Frontiers in Astronomy and Space Sciences}, volume = {13}, year = {2026}, month = {03/2026}, abstract = {

High-frequency (HF) skywave propagation relies on the ionosphere, making it susceptible to ionospheric variability. This study analyzes long-term Doppler residual measurements of a 10 MHz HF link between Fort Collins, CO, and Newark, NJ, to characterize the impact of ionospheric conditions on the link. We report that daytime measurements of Doppler variability exhibit Cauchy statistics, while nighttime measurements show a combination of exponential and log-normal statistics. These patterns correlate with solar activity and solar zenith angle. We also use PHaRLAP numerical ray tracing simulations through the IRI 2020 ionosphere to provide insights into signal ray paths and the altitudes of the ionosphere contributing to the observed Doppler shifts. By examining diurnal variations and statistical properties of Doppler residuals, this study aims to enhance our understanding of ionospheric dynamics and their influence on HF signal characteristics.

}, doi = {10.3389/fspas.2026.1713968}, url = {https://www.frontiersin.org/articles/10.3389/fspas.2026.1713968/fullhttps://www.frontiersin.org/articles/10.3389/fspas.2026.1713968/full}, author = {Fernandes, Sabastian and Perry, Gareth W. and Trigo, Tiago and Frissell, Nathaniel A. and Gibbons, John and Collins, Kristina} } @article {1056, title = {HamSCI HF multipath propagation mode analysis using amateur radios and audio waveforms sensitive to time difference of arrival}, journal = {Frontiers in Astronomy and Space Sciences}, volume = {13}, year = {2026}, month = {03/2026}, abstract = {

This study describes a method to deduce the ionization layer virtual height and propagation path geometry responsible for communication between two HF radio stations a fixed distance apart. The method measures the Time Difference of Arrival (TDOA) between multipath propagation modes involving the active ionospheric layers and reconciles the data with a virtual height model of the ionosphere. The TDOA approach was implemented by transmitting audio signals that are sensitive to a time delay when summed together as happens in a receiver during multipath reception. The TDOA method eliminates the need for any absolute time references or extensive equipment calibration that would be required for an absolute time of flight (TOF) measurement. The audio waveforms used by the method included 1-cycle audio bursts, linear audio chirps of controlled sweep rate, and pseudorandom noise (PN) bursts.

}, doi = {10.3389/fspas.2026.1723511}, url = {https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2026.1723511/full}, author = {Cerwin, Stephen A. and McMahan, Jesse T. and Papadopoulos, Alexandros S. and Piccini, Gerard N. and Frissell, Nathaniel A. and Collins, Kristina V. and Montare, Aidan and Bilberry, Paul and Blackshear, Samuel and Themens, David R.} } @proceedings {1010, title = {HamSCI Link Budget: Observations and Modeling the Signal Strength of HF Radio Links from WWV to W2NAF}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {

This work explores the ionospheric High Frequency (HF) absorptions, specifically at 5 and 10 MHz. We investigate the HF absorption levels for the radio links from the two National Institute of Standards and Technology (NIST) dedicated Radio transmitting Stations, WWV Colorado and WWV Hawaii, to the Personal Space Weather Station (PSWS) receiver W2NAF. W2NAF, located near Scranton, Pennsylvania, is equipped with the GPS-disciplined Great Radio Amateur Propagation Experiment (GRAPE) receiver. Our work utilizes the International Reference Ionosphere (IRI-2020) model and PHaRLAP ray tracer to calculate the absorptions of the HF rays from the two WWV transmitters to W2NAF connected by 1, 2, or 3 hop links. For the modeled rays, we also calculate the percentage of successful rays connecting WWV and W2NAF. Our results show that the modeled absorptions are consistent with the signal strength observations for some of the quiet days, albeit with divergences at others. We will present these results on the data-model comparison of the Ham Radio Science Citizen Investigation (HamSCI) link budget.

}, author = {Gamal Zayed and Kuldeep Pandey and Nathaniel Frissell} } @proceedings {1022, title = {A Low-Cost Low-Power Chirp Ionosonde for Studying the Ionospheric Impacts of Space Weather}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {The ionosphere is a region of the atmosphere characterized by both ions and electrons. It is highly active and experiences changes in parameters such as electron density at different altitudes, based on the energy absorbed from the sun. Ionosondes are a type of radar used to gather data about the height of the ionosphere by transmitting a signal towards the ionosphere. This signal is refracted back to the Earth{\textquoteright}s surface and received in such a manner that return echoes can be timed to calculate the height profile of the bottomside ionosphere. Traditional ionosondes require large antenna systems and high amounts of power. Recent advancements in software defined radio (SDR) technology, advanced digital signal processing, and computational efficiency enable the size, cost, and power demands of an ionosonde system to be reduced. An Ettus N200 Universal Radio Peripheral was used in our system to verify the reliability of our methods, and during the 2024 total solar eclipse, the system was successfully used to sound the ionosphere. It recorded virtual layer height data comparable to multimillion-dollar ionosonde systems. Since then, we have updated the system to use the newer Red Pitaya SDRlab 122-16. This more affordable board is able to sound the ionosphere, using the same methods as the Ettus based system. Additionally, the system is now in a smaller and more portable form. Currently, we are improving its ability to collect data automatically and be controlled remotely. Furthermore, we are continuing to improve our sounding methods to obtain more data using the same hardware.}, author = {Gerard Piccini and Andrew Rodland and Robert McGwier and Robert Spalletta and Nathaniel Frissell and Majid Mokhtari and Philip Erickson} } @proceedings {1014, title = {Multi-Year Climatology of Large-Scale Traveling Ionospheric Disturbances Observed with High Frequency Amateur Radio Receiving Networks Using a Novel Automated Detection Algorithm}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {We present a fully automated, deterministic technique for detecting and characterizing Large Scale Traveling Ionospheric Disturbances (LSTIDs) using 14 MHz amateur (ham) radio data. The method isolates wave periods between 1{\textendash}5 hours and applies sinusoidal curve fitting to the first-hop skip-distance edge of observed communication ranges, yielding quantitative estimates of LSTID amplitude and period. Data from the Weak Signal Propagation Reporting Network (WSPRNet), the Reverse Beacon Network (RBN), and PSKReporter, which is now merged and available on the CEDAR Madrigal database, were used produce a unified multi-year climatology of LSTID activity over the continental United States (2016{\textendash}2023). Results show clear seasonal patterns: enhanced LSTID occurrence during winter, weaker activity in spring and fall, and modest summer increases. These results are consistent with prior studies and suggest modulation by neutral wind filtering, sudden stratospheric warming (SSW), vertical coupling, and solar activity.}, author = {Diego Sanchez and Mary Lou West and Nathaniel Frissell and Gareth Perry and V. Lynn Harve and Bill Engelke and Nicholas Callahan and Philip Erickso and Erich Becker and Sharon Vadas} } @proceedings {1045, title = {Personal Space Weather Station Observations of the Gannon Geomagnetic Storm}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {The geomagnetic storm known as the Gannon Storm took place from 10-13 May 2024. Classified as a G5 geomagnetic storm, the Gannon Storm was the most extreme event of its kind to occur in the past two decades. Space weather events of this magnitude have significant impacts on orbiting satellites, navigation systems, power grids, and communications. Particularly, geomagnetic storms are known to disrupt technologies that utilize the high frequency (HF) portion of the radio spectrum. The aim of this study is to understand the Gannon Storm{\textquoteright}s effects on HF propagation. Using the Ham Radio Science Citizen Investigation{\textquoteright}s network of personal space weather stations (PSWSs), Doppler shift data gathered during the Gannon Storm is examined and compared against data collected on days with quieter geomagnetic conditions. PSWS receivers detected elevated Doppler shifts among traveling HF signals and more interruptions to the signals than is typical. Studying the Gannon Storm{\textquoteright}s effects on HF propagation can inform how technologies that rely on these frequencies may be better equipped against similar extreme space weather events in the future.~~~}, author = {Rebecca Potter and Nathaniel Frissell and Gwyn Griffiths and Kuldeep Pandey} } @proceedings {1048, title = {Phase Coding in Digital SuperDARN Radars to Observe Oblique Scattering}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {Super Dual Auroral Radar Network (SuperDARN) is a network of HF radars in the mid to high-latitude regions that observe space weather effects on the ionosphere and magnetosphere. These radars typically transmit a single frequency multi-pulse sequence in the 8-22MHz range in a monostatic configuration. Between 2019 and 2020, two radars were reconfigured at certain times to carry out bistatic operations to demonstrate detecting oblique scatter. These operations were limited to intersecting fields-of-view of both radars, and forcing one radar to be receive-only, disrupting regular radar operation. The results of these operations showed a need for a more flexible approach that is not constrained by mode or field-of-view. Since then, some radars in the network have been converted to a Software Defined Radio (SDR) based system. An SDR-based system enables greater configurability in the transmit waveform the radar uses, including the possibility to encode unique radar IDs into the pulse. Operating modes incorporating phase coding are currently in use for their increased range resolution, so phase coding an ID in the transmit pulse would not affect the normal operation of the radar. This work proposes that SuperDARN radar waveforms with phase-coded IDs could be received by low-cost SDRs similar to the PSWS Grape receivers, to study propagation and oblique scattering in the ionosphere.}, author = {Allison Pitzl and Kevin Sterne and Mike Ruohoniemi and Joseph Baker and Bharat Kunduri and Nathaniel Frissell} } @proceedings {1037, title = {Solar Eclipse Through Ham Radio: What the Bands Revealed}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, author = {Kuldeep Pandey} } @proceedings {931, title = {Analysis by Citizen Scientists of Doppler Radio Observations of the April, 2024 Solar Eclipse}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI community (Ham Radio Science Citizen Investigation) has analyzed high frequency radio observations of the total solar eclipse of April 8, 2024 and found interesting correlations. Nearly fifty ham radio operators recorded over 200 Doppler time series of the national time standard transmitters WWV in Colorado and CHU in Canada using specialized GRAPE (Great Radio Amateur Propagation Experiment) receivers. These observations are archived at the Personal Space Weather Station website, and cover ten frequencies from 0.6 to 25 MHz. There were over sixty different paths from transmitter to receiver at various angles across and along the path of totality from Texas to Maine. For each observation six citizen scientists collected demographic data, found distances and midpoints (where radio signals are reflected from the ionosphere), noted local eclipse information, measured the maximum Doppler shifts, counted multi-path signals, and judged the symmetry of the S-shaped Doppler curves over ingress and egress time periods. We found that the Doppler shifts depend mostly on the Sun{\textquoteright}s obscuration at the midpoint, but also on the carrier frequency and the distance between the transmitter and the receiver. At closer distances a radio wave measured a greater change in the path length as the bottom of the ionosphere retreated skyward and then returned as the Moon uncovered the Sun. \ 

}, author = {Mary Lou West and Nathaniel Frissell and Gary Mikitin and Gregory Popelas and Ronald Wilcox and McKenzie Denton and Robert Spalletta and William Engelke and Gwyn Griffiths and Steve Cerwin} } @proceedings {932, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The objective of our research is to use narrowband linear audio pulses, which are sensitive to time displacement, and transmit them through High Frequency (HF) commercial off-the-shelf (COTS) single-sideband (SSB) amateur radios to measure changes in ionospheric reflection heights, specifically during a solar eclipse. This will be accomplished and automated using programming techniques learned in the Digital Signal Processing course at the University of Scranton, where the primary objective is to use TDOA (Time Difference of Arrival), a technique that measures the time displacement of single/multiple paths as they reach a receiving station. These TDOA values will be manipulated using a virtual height model that will yield different values of ionospheric layer heights based on the locations of the receiving and transmitting stations. During the October 2023 and April 2024 solar eclipses, WA5FRF transmitted a series of linear audio pulses (chirps) every 10{\textendash}15 minutes to various receiving stations on the 5, 7, and 14 MHz amateur radio bands. Received signals were squared and filtered to detect the waveform envelope. Correlation with a matched signal was then used to identify the start time of each chirp, after which a Fast Fourier Transform (FFT) was used to identify the beat-note frequency generated by multipath propagation. The October 2023 eclipse automated analysis shows that the F region reflection point was raised from 262.5 km at 17:00 UTC to 300 km at eclipse maximum at 17:30 UTC. The April 2024 eclipse analysis shows no real maximum reflection point; however, it does indicate an increase in layer height following maximum obscuration at 18:30 UTC. Both analyses are in good agreement with the hmf2 observations of the Austin Ionosonde. The intended purpose was to monitor multipath interference for 1{\textendash}2 hops off of the F2 layer; however, recent developments in this automated process yield additional data for other modes.

}, author = {Alexandros Papadopoulos and Gerard Piccini and Nathaniel Frissell and Steve Cerwin and Jesse McMahan and Paul Bilberry and Blackshear Samuel and Aidan Montaigne and Kristina Collins and Robert Spalletta} } @proceedings {949, title = {Climatology of Large-Scale Traveling Ionospheric Disturbances Observed with 14 MHz Amateur Radio Using a Novel Automated Detection Technique}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present a multi-year climatology of Large Scale Traveling Ionospheric Disturbance (LSTID) period oscillations observed using 14 MHz amateur (ham) radio data. Traveling ionospheric disturbances (TIDs) are quasi periodic electron density perturbations in the F region ionosphere that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. These are seen, in daytime, as variations in contact ranges in 14 MHz amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet), the Reverse Beacon Network (RBN), and PSKReporter. A new deterministic and fully automated method was developed for identifying and quantifying these disturbances. This technique, which filters for TID wave periods between 1 and 5 hours and curve fits a sinusoidal function to the first hop skip-distance edge of observed communication ranges, provides both TID amplitudes and periods. In this study, we present full year climatologies of LSTID events over the continental United States (CONUS) using RBN, WSPRNet, and PSK observations from 2016- 2021. Results are organized as a function wave period, amplitude, and season. We find that LSTIDs increase in winter and decline during the fall and spring, with slight enhancements in the summer and occasional brief declines in LSTID winter activity. This seasonal pattern shows consistency with previous studies and observations of LSTIDs and medium scale TIDs that suggests this behavior may be associated with neutral wind filtering in the middle atmosphere, sudden stratospheric warming (SSW) events, and multi-step vertical coupling (MSVC) processes. MSVC is a process where gravity waves (GWs) from the lower neutral atmosphere propagate upwards, break, and produce new, higher-order GWs in the thermosphere and TIDs in the ionosphere.

}, author = {Diego Sanchez and Nathaniel Frissell and Mary Lou West and V. Lynn Harvey and Sharon Vadas and Erich Becker and Gareth Perry and William Engelke and Nicholas Callahan and Philip Erickson} } @proceedings {973, title = {Electron thermionic emission and tunneling transport in spherically symmetric charged grains in dusty plasmas}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Electron emission from charged spherical dusty grains plays a crucial role in plasma environments, influencing charge dynamics and transport properties. This presentation explores thermionic emission and quantum tunneling as potential escape mechanisms for electrons in such systems. Using the Richardson-Dushman equation, we estimate thermionic emission currents at high temperatures, revealing significant electron loss under extreme conditions. Additionally, we analyze the feasibility of quantum tunneling, incorporating Debye shielding effects to assess barrier modifications and electron transmission probabilities. Our findings suggest that while thermionic emission dominates at elevated temperatures, tunneling can contribute non-negligibly in dense plasma conditions, influencing overall charge equilibrium. A promising direction for future probing is the impact of dynamic charge fluctuations on tunneling probabilities, which could further refine our understanding of electron escape processes in fluctuating plasma environments.

}, author = {Rebecca Potter and Nina Tormann and Argyrios Varonides} } @proceedings {929, title = {HamSCI Solar Eclipse QSO Party (SEQP): Observations and Modeling on Ionospheric Effects}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

This study investigates the ionospheric changes during the solar eclipse of April 2024 using data from the HamSCI Solar Eclipse QSO Party (SEQP). SEQP collected radio communication data reported by ham radio operators and global automated receiving networks (e.g., WSPRNet, the Reverse Beacon Network, and PSKReporter). The datasets include radio communications at multiple frequencies in the high frequency (HF) and very high frequency (VHF) bands. Thousands of ham radio operators across the contiguous United States (CONUS) and around the globe contributed to the observations with unprecedented temporal, spatial, and spectral coverage. SEQP datasets are used to infer ionospheric state before, during, and after the solar eclipse. We use the ham radio datasets along with PHaRLAP raytrace modeling to infer the ionospheric response of the solar eclipse and also evaluate the outputs of the physics-based model SAMI3 for the eclipse ionosphere. Our findings suggest that the solar eclipse increased the range of radio communications at lower HF band (3.5, 7, 10 MHz), but decreased the longer range communications at higher HF band (21, 24, 28 MHz). Ham radio datasets from stations continually operated during the eclipse show an earlier opening of radio links between the US and Europe on the eclipse day. We are conducting modeling studies to understand the causes of changes in ham radio observations and to examine the potential combined effect of the sunset terminator and eclipse shadow during the later phase of the eclipse.

}, author = {Kuldeep Pandey and Gareth Perry and Nathaniel Frissell and Travis Atkinson and William Engelke and Joseph Huba and Mary Lou West and Philip Gladstone and Cameron Cushing and McKenzie Denton and Edward Efchak and Gary Mikitin and H. Ward Silver} } @proceedings {935, title = {High-Frequency Signal Strength Simulation at GRAPE Personal Space Weather Stations Using PHaRLAP Ray Tracing}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

High-frequency (HF) radio wave propagation serves as both a vital communication tool and a probe for ionospheric behavior. This work models and analyzes the reception of HF signals from the standard transmitting station WWV (Fort Collins, Colorado) to two well-calibrated Personal Space Weather Stations (PSWS): W2NAF (Scranton, Pennsylvania) and K6KPH (Point Reyes, California). These stations are equipped with Great Radio Amateur Propagation Experiment (GRAPE) receivers{\textemdash}GPS-disciplined systems designed to measure standard time signals with high precision. To simulate HF wave propagation, we use the Provision of High-Frequency Raytracing Laboratory for Propagation Studies (PHaRLAP), a MATLAB toolbox for ionospheric ray tracing. Utilizing the data-based International Reference Ionosphere (IRI) 2020 model, which supplies the ionospheric background conditions, we analyze HF propagation at 5, 10, and 15 MHz by launching a fan of rays at varying elevation angles to determine which rays successfully reach the receivers. In addition, we are extending our simulations using the Python-based SAMI3 ionospheric model. We also compute ionospheric HF absorption and compare the modeled values with the observed signal strengths recorded by the PSWS throughout the day, aiming for the predicted absorption to be within one order of magnitude of the observations. This work enhances our understanding of how ionospheric absorption affects HF signal strength across different times of day and seasons, thereby contributing to space science, space weather research, and amateur radio science.

}, author = {Gamal Zayed and Nathaniel Frissell and Kuldeep Pandey} } @proceedings {957, title = {How Do We Put a HamSCI Personal Space Weather Station in Antarctica?}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present initial ideas on how to place a HamSCI Personal Space Weather Station at United States Antarctic Research Stations.

}, author = {Rebecca Potter and Nina Tormann and Christine Zakzewski and Majid Mokhtari and Nathaniel Frissell and Ken Martin and Jermey McLynch and Hyomin Kim and Gareth Perry and David McGaw and James LaBelle and Tedi Godfrey and Michael Hartje and Gwyn Griffiths and Rob Robinett and Paul Elliott} } @proceedings {975, title = {Incorporating HamSCI Project into a College Physics Course: A Progress Report}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We report on citizen science activities in a physics course and Space Force ROTC training designed to engage undergraduate students and cadets in the HamSCI Personal Space Weather Station (PSWS) project. The New Jersey Institute of Technology (NJIT) Physics Department offers a senior-level lab course, "Advanced Physics Lab," where students are expected to gain hands-on experience with experimental techniques, instrumentation, theoretical and applied electronics, solid-state electronic devices, and experiments in modern physics by performing quantitative measurements of fundamental physical parameters. In this lab, students work in a largely unstructured environment, where they are provided with equipment and related manuals to conduct experiments with minimal instructor supervision. Traditionally, students have followed preset lab setups, guided by the manuals that accompany the equipment. While this approach helps students relate lab results to established physics theories and principles, its impact has been limited due to a lack of "hands-on" experience and real-world application demonstrations. The HamSCI PSWS project provides an excellent opportunity to address this gap. Through the project, students build and test scientific instruments, using them for investigations that engage them directly in scientific inquiry. This paper presents an evaluation of the impact of this undergraduate class activity on future workforce development, utilizing HamSCI resources.

}, author = {Hyomin Kim and Jeremy McLynch and Joseph Visone and Dominick Santelli and Sergio Santelli and Gareth Perry and Nathaniel Frissell and Gary Mikitin and John Gibbons and David Witten} } @proceedings {953, title = {Integration \& Validation of a Standardized Library \& File Format for PyDARNMUSIC \& DARNtids: Migrating From Legacy Pickle Files to HDF5 \& Implementing a Comprehensive Testing Suite}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The PyDARN Multiple Signal Classification (PyDARN-MUSIC) algorithm is a general, widely used sign processing algorithm for determining the parameters of multiple wavefronts arriving at an antenna array from measurements made on the signals received at the array elements. It has been used in previous Super Dual Auroral Radar Network (SuperDARN) studies to determine the size, strength, speed, and direction of Medium Scale Traveling Ionospheric Disturbances (MSTIDs). DARNtids (Dual Auroral Radar Network Traveling Ionospheric Disturbances) is a python-based open-source software toolkit that first detects level of MSTID activity in SuperDARN data and then runs the MSTID MUSIC analysis software on event periods with significant MSTIDs. DARNtids can run the SuperDARN MUSIC algorithm automatically on thousands\  individual analysis periods. Both PyDARN-MUSIC and DARNtids use pickle files for storing Python objects\  byte streams. Pickle files are fragile and cannot be easily manipulated and used on modern systems. They are specific to Python, produce massive serialized values, and are slower than alternative options. As result, both repositories have experienced software engineering challenges related to portability, interoperability, testability, and maintainability, thereby forcing runs to take significantly longer than necessary, data to be stored inefficiently, and the debugging process to be difficult. We present the methodology taken to seamlessly replace dependencies on pickle files in PyDARN-MUSIC and DARNtids integrating the Hierarchical Data Format Version 5 (HDF5) file format and library. We further discuss validation techniques via the newly implemented PyDARN-MUSIC test suite to ensure numerical data accuracy between existing pickle file results and new HDF5 result.

}, author = {Nicholas Guerra and James Fox and Thomas Pisano and Michael Molzen and Nathaniel Frissell and Paul Jackowitz and Joseph B. H. Baker and J. Michael Ruohoniemi} } @proceedings {936, title = {Ionospheric Variability{\textquoteright}s Impact on HF Propagation: Insights from Grape V1 Doppler Residuals and PHaRLAP Ray Tracing}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

This study investigates the impact of ionospheric variability on HF (3-30 MHz) skywave propagation, a critical aspect of long-range radio communication. Using a dedicated HamSCI Grape V1 low-IF receiver (K2MFF) at NJIT, we analyze long-term Doppler residual measurements of the 10 MHz WWV signal from Fort Collins, CO. Our observations reveal a strong correlation between stable daytime propagation and a Cauchy distribution of Doppler residuals, while sporadic nighttime conditions align more with a combination of exponential power and log-normal statistics. This pattern is consistent across our dataset, barring dates of atypical solar irradiance on the ionosphere, such as during high-class solar flares and solar eclipses. We compare these findings with PHaRLAP ray-tracing simulations using an IRI ionosphere model, allowing us to visualize the signal{\textquoteright}s ray path and pinpoint the ionospheric altitudes (100-400 km) responsible for observed features. Raytracing results attribute daytime signal stability to a superposition of multi-hop modes, while nighttime oscillations linked to TIDs are measurable due to 1-hop dominance. By examining diurnal variations in Doppler residuals, this work provides amateur radio operators with a better understanding of ionospheric dynamics and their impact on HF communication, ultimately contributing to improved prediction of propagation conditions and more effective use of the HF spectrum. Additionally, this work provides a foundation for interpreting real-time propagation data and understanding the effects of solar activity and ionospheric variations on signal quality and reliability for amateur radio communication.

}, author = {Sabastian Fernandes and Gareth Perry and Tiago Trigo and Nathaniel Frissell and John Gibbons} } @proceedings {961, title = {A Low-Cost Low-Power Chirp Ionosonde for Studying Eclipse Ionospheric Impacts}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The ionosphere is a region of the atmosphere characterized by both ions and electrons. It is highly active and experiences changes in parameters such as electron density at different altitudes, based on the energy absorbed from the sun. Ionosondes are a type of radar used to gather data about the height of the ionosphere by transmitting a signal towards the ionosphere.\  This signal is refracted back to the Earth{\textquoteright}s surface and received in such a manner that return echoes can be timed to calculate the height profile of the bottomside ionosphere. Traditional ionosondes require large antenna systems and high amounts of power. Recent advancements in software defined radio (SDR) technology, advanced digital signal processing (DSP), and computational efficiency enable the size, cost, and power demands of an ionosonde system to be reduced. Two systems are currently used in this project: the Ettus N200 Universal Radio Peripheral (USRP) and the newer Red Pitaya SDRlab 122-16. Using amateur radio fan dipoles and GNU Radio code, the Ettus system was used successfully to sound the ionosphere during the 2024 total solar eclipse. It recorded virtual layer height data comparable to multimillion-dollar ionosonde systems. We are now working to assemble the Red Pitaya system into a smaller form that can be assembled inexpensively and operated with ease. In the following weeks we will improve our sounding methods to be able to obtain more data.

}, author = {Gerard Piccini and Robert McGwier and Robert Spaletta and Nathaniel Frissell and Majid Mokhtari and Philip Erickson} } @proceedings {970, title = {Southern Hemisphere MSTID response to a Sudden Stratospheric Warming Observed by the Falkland Islands SuperDARN Radar}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present a study of Medium Scale Traveling Ionospheric Disturbances (MSTIDs) observed by the Falkland Islands Radar (FIR) in the Southern Hemisphere in response to a sudden stratospheric warming (SSW) event. MSTIDs are quasi-periodic variations in the upper atmospheric (~250 km altitude) plasma with phase speeds of ~100-250 m/s, periods from ~15-60 minutes, and horizontal wavelengths of several hundred kilometers. Daytime MSTIDs are known to be associated with gravity waves (GWs) that originate in the lower and middle atmosphere and propagate upward into the F-region. Neutral wind filtering of these GWs creates a strong dependence of GW-associated MSTIDs on stratospheric and mesospheric zonal wind direction and speed, which is tied to polar vortex strength during fall, winter, and spring months. This dependence manifests as both seasonal and sub-seasonal variability of MSTID amplitudes. Most existing SuperDARN MSTID studies have focused on observations from the Northern Hemisphere. This work uses an automated spectral approach previously used to study Northern Hemisphere winter daytime SuperDARN MSTIDs and applied it to all radars in both hemispheres for all times of day and all seasons for the years 2010-2021. This helped us identify the Southern Hemisphere radars with the highest quality data. One radar for which the retrievals worked particularly well was FIR which illustrates suppressed MSTID activity following the minor SSW beginning on 6 September 2019. This suggests that Southern Hemisphere MSTIDs, like their Northern Hemisphere counterparts, have GW sources in the lower/middle neutral atmosphere and are modulated by the polar vortex jet.\ 

}, author = {James Fox and Nicholas Guerra and Thomas Pisano and Michael Molzen and Nathaniel Frissell and Lynn Harvey and Joseph Klobusicky and Mark Fenner and Joseph Baker and Michael Ruohoniemi} } @proceedings {976, title = {University of Scranton W3USR Teaching Amateur Radio at the Lackawanna Blind Association}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Access to amateur radio can be life-changing for individuals who are blind or visually impaired. Radio communication provides an accessible, independent, and engaging way to connect with others; it helps foster both technical skills and social interactions. The University of Scranton W3USR, working in collaboration with local amateur radio operators and the Lackawanna Blind Association (LBA), has launched a program to teach amateur radio to people who are blind and visually impaired using the Handiham curriculum. This initiative enables blind and visually impaired individuals to engage with and become licensed amateur radio operators through an accessible learning experience that they look forward to each week. This project has support from all different angles and has shown some promising results.

}, author = {Thomas Pisano and Owen Ruzanski and Alexandros Papadopoulos and Lucero Alvarez and Ken Martin and William Gallagher and Christine Zakzewski and Nathaniel Frissell} } @proceedings {858, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The objective of our research is to analyze the effects of a solar eclipse on High Frequency (HF) radio by extracting the time difference of arrival (TDOA) due to multiple ionospheric paths of ~3 kHz bandwidth chirp signals sent and received with unmodified commercial off-the-shelf (COTS) single sideband (SSB) amateur radio transceivers. We use programming techniques learned in the Digital Signal Processing course at The University of Scranton in the Python language to automate this process. On the day of the 14 October 2023 eclipse in Texas, WA5FRF transmitted a series of chirps every 15 minutes to receiving stations N5DUP and AB5YO on 5.3 MHz and 7.2 MHz. Received signals were digitized, then squared and low-pass filtered to detect the waveform envelope. Correlation with a matched signal is then used to identify the start time of each chirp, after which a Fast Fourier Transform (FFT) is used to identify the beat-frequency (and TDOA value) generated by the multipath propagation. This TDOA value is then used to compute an ionospheric reflection height. On the WA5FRF-N5DUP path, this analysis shows that the F region reflection point raised from 262.5 km at 17:00 UTC to 300 km at eclipse maximum at 17:30 UTC and then returned to approximately 280 km at 18:00 UTC. This result is in good agreement with the hmF2 observations of the Austin ionosonde.

}, author = {Alexandros Papadopoulos and Gerrard Piccini and Thomas Pisano and Nicholas Guerra and Matthew Felicia and Evan Hromisin and Aidan Montare and Kristina Collins and Paul Bilberry and Samuel Blackshear and Steve Cerwin and Nathaniel A. Frissell} } @proceedings {822, title = {Considering the Sudden Loss of WWV{\textquoteright}s signal as seen by HamSCI Grape Stations}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Sudden unexplained dropouts of WWV{\textquoteright}s signal as seen by Grape stations are explained and illustrated using Maximum Usable Frequency (MUF) maps.

}, author = {George Kavanagh and Robert Reif and Stanley Pozerski and Peter Nordberg and William Blackwell} } @proceedings {823, title = {Exploring Ionospheric Variability Through Doppler Residuals: A Study Utilizing the HamSCI Grape V1 Receiver}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

This study leverages the capabilities of the Grape V1 low-IF receiver to analyze both long and short-term patterns of high frequency (HF; 3-30 MHz) skywave signals. The HF spectrum, often used for global long-range communications, also spans the frequencies used for remote sensing of the near-Earth plasma environment. The Grape receiver (callsign K2MFF) used in this study is located at the New Jersey Institute of Technology (NJIT) in Newark, NJ. At a rate of 1 Hz, it samples its link to the WWV broadcasting station transmitting at 10 MHz from Fort Collins, CO. The Doppler shift in this radio link, caused by its interactions with the ionosphere, is measured to study fluctuations in the ionosphere{\textquoteright}s electron density. This methodology provides insight into the effects of geomagnetic activity on the terrestrial ionosphere, caused by complex processes in the coupled Sun-Earth plasma environment. Our results show that the signal received during the daytime is less prone to Doppler shift than when received during the nighttime. This night-day contrast is consistent across most 24-hour cycles, barring dates of antenna maintenance or severe geomagnetic storms. We also found a strong correlation between daytime measurements and Cauchy statistics, and between nighttime measurements and a mixture of exponential power / lognormal statistics, wherein day and night at the geographic midpoint between WWV and NJIT are considered. The identification of these differing statistical regimes per time of day has led us to characterize long-term trends in the dataset by the medians of day and night Doppler measurements, independently. Additionally, the receiver{\textquoteright}s sensitivity and versatility was affirmed through case-studies of atypical Doppler traces captured in the data stream, by identifying characteristic markers of solar flares and solar eclipses.

}, author = {Sabastian Fernandes and Gareth W. Perry and Tiago Trigo and Nathaniel A. Frissell and John Gibbons} } @proceedings {862, title = {Incorporating HamSCI Project into a College Physics Course}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

We report citizen science activity in a physics course to engage undergraduate students in a HamSCI Personal Space Weather Station (PSWS) project. The New Jersey Institute of Technology (NJIT) Physics Department has been offering a senior-level lab course, "Advanced Physics Lab" in which the students are expected to gain experience with experimental techniques, instrumentation, theoretical and applied electronics, solid state electronic devices, experiments in modern physics by performing quantitative measurements of fundamental physical parameters. Students perform lab experiments in a mostly unstructured setting, in which students are given the equipment and related manuals and perform experiments with very minimal instructor{\textquoteright}s supervision. Historically, the students have been given a pre-set lab equipment by following the manuals accompanied by the equipment. While this may be suitable for providing an opportunity for the students to relate the results in the lab with the known physics theories/principles, the impact to the students is limited as there is still insufficient "hands-on" components and demonstration of real-world applications. The HamSCI PSWS project is a good example in which students build and test science instruments and use them for scientific investigations to address this issue. We present undergraduate class activity and evaluate their impact on future workforce training utilizing the HamSCI resources.\ 

}, author = {Hyomin Kim and Lindsay Goodwin and Gareth Perry and Nathaniel A. Frissell and Gary Mikitin} } @proceedings {857, title = {A Low-Cost Low-Power Chirp Ionosonde for Studying Eclipse Ionospheric Impacts}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The ionosphere is a region of the atmosphere characterized by both ions and electrons. It is highly active and experiences changes in parameters such as electron density at different altitudes, based on the energy absorbed from the sun.\  Ionosondes are a type of radar used to gather data about the height of the ionosphere by transmitting a signal towards the ionosphere.\  This signal is refracted back to the Earth{\textquoteright}s surface and received in such a manner that return echoes can be timed to calculate the height profile of the bottomside ionosphere. Traditional ionosondes require large antenna systems and high amounts of power. Recent advancements in software defined radio (SDR) technology, advanced digital signal processing (DSP), and computational efficiency enable the size, cost, and power demands of an ionosonde system to be reduced. In this poster, we present our recent efforts to implement a low-cost, low power ionosonde. Two systems are currently used in this project: the Ettus N200 Universal Radio Peripheral (USRP) and the newer Red Pitaya SDRlab 122-16. The Red Pitaya system is still being developed while the Ettus enables us to test the rest of the hardware and collect data during the 2024 eclipse. Using amateur radio fan dipoles and GNU Radio code, the system will sound the ionosphere during the upcoming eclipse. Over the following weeks the system will be improved in preparation for the upcoming eclipse.

}, author = {Gerard Piccini and Robert McGwier and Robert A. Spalletta and Nathaniel A. Frissell} } @proceedings {836, title = {Possible Drivers of Large Scale Traveling Ionospheric Disturbances by Analysis of Aggregated Ham Radio Contacts}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasiperiodic electron density perturbations of the F region ionosphere that have periods of 30 min to over 180 min, wavelengths of over 1000 km, and velocities of 150 to 1000 m/s. These are seen as long slow oscillations in the bottom side of the ionosphere in data from ham radio contacts at 20 meters wavelength on roughly a third of the days in a year. They might be triggered by electromagnetic forces from above, and/or by mechanical pressures from below. The explosion of the Tonga volcano on January 15, 2022 revealed that such a LSTID could be triggered by a violent updraft from the Earth{\textquoteright}s surface into the stratosphere and then detected in the ionosphere over the United States nine hours later. We consider other possible drivers such as the auroral electrojet, the polar vortex, thunderstorms, zonal wind speeds, gravity wave variances, and their time derivatives in 2017.

}, author = {Diego Sanchez and Mary Lou West and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Robert B. Gerzoff and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker and V. Lynn Harvey} } @proceedings {876, title = {Reworking the MUSIC Algorithm to Mitigate MSTID Direction Estimation Bias Associated with SuperDARN Radar Field-of-View Geometry}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are variations in the F region ionospheric electron density. MSTIDs can be associated with atmospheric gravity waves (AGWs) and provide critical information for understanding the ionosphere, which is an electrically charged region of the atmosphere. Previous SuperDARN studies of MSTIDs have used the Multiple Signal Classification (MUSIC) algorithm to determine the size, speed, and direction of these disturbances in the ionosphere. Upon analyzing MSTID MUSIC results from ten North American SuperDARN radars over a period of twelve winter seasons (2010-2022), we found a bias in the SuperDARN MSTID MUSIC direction estimation algorithm that preferentially reports waves as traveling along the boresight direction of the radars. We demonstrate that this bias is caused by the radar Field-of-View geometry and report on the progress algorithm development for removing this bias.

}, author = {Michael Molzen and Thomas Pisano and Nicholas Guerra and Juan Serna and Nathaniel A. Frissell} } @proceedings {871, title = {Signatures of Space Weather in the NJIT V1 Grape Low-IF Receiver}, year = {2024}, month = {03/2024}, abstract = {

The V1 Grape Low Intermediate Frequency (Low-IF; 10 MHz) Receiver is part of a low-cost Personal Space Weather Station (PSWS) developed by the Ham Radio Science Citizen Investigation (HamSCI) Collective. One of the existing deployed Grapes is located at the New Jersey Institute of Technology (NJIT). The Grape measures the WWV 10 MHz signal originating from Fort Collins, Colorado. Variations in WWV{\textquoteright}s signal intensity and frequency, received by the Grape can be used to investigate\  strong space weather events and their effects on the Earth{\textquoteright}s ionosphere. The Grape data is separated into two parameters, Doppler Shift (Hz) which is a change in frequency introduced by the variability of the ionosphere along the WWV to NJIT link, and Relative Power (dB) which can be used as a proxy for the received signal{\textquoteright}s intensity.\  In this presentation, we will explore the possibility of using the Relative Power parameter for studying ionospheric scintillation due to space weather events.\  We will present several examples of data collected on days with known space weather events to assess the Grape{\textquoteright}s ability to detect the event. We will also discuss our analysis techniques, including our strategies to mitigate the local noise environment at NJIT, and future work.

}, author = {Tiago Trigo and Gareth W. Perry and Sebastian Fernandes and John Gibbons and Nathaniel A. Frissell} } @proceedings {734, title = {Climatology of Large Scale Traveling Ionospheric Disturbances Observed with Amateur Radio Networks}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A new climatology of Large Scale Traveling Ionospheric Disturbances (LSTIDs) has been observed from ham radio data in 2017. LSTIDs are quasiperiodic electron density perturbations of the F region ionosphere. LSTIDs have periods of 30 min to over 180 min, wavelengths of over 1000 km, and velocities of over 1400 km/hr. In this paper, we show a climatology of observed LSTID events using data from the Reverse Beacon Network (RBN), Weak Signal Propagation Network (WSPRNet), and PSKReporter amateur radio networks. This climatology was performed twice and was cross examined between two members of the research team. Results show that most of the observed LSTIDs occurred during the winter months with a decline towards the summer, with the exception of a spike in June. This paper provides additional insight into the seasonal trends of LSTIDs and provides additional knowledge that will help in the pursuit of what is causing this phenomenon.

}, author = {Diego Sanchez and Mary Lou West and Bob Gerzoff and Gareth W. Perry and Nathaniel A. Frissell and William D. Engelke and Philip J. Erickson} } @proceedings {744, title = {FDTD for Geophysical Applications}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The finite-difference time-domain (FDTD) method [Yee, IEEE TAP, 14:3, 1966] is a robust method that solves Maxwell{\textquoteright}s equations in time and over a spatial grid.\  It can account for arbitrary source time-waveforms as could occur from man-made antennas as well as naturally occurring ionospheric currents or lightning strikes, etc.\  The FDTD method can also account for complex 3-D geometries, including for example a variable ground topography and 3-D lithosphere/ionosphere compositions.\  By coupling Maxwell{\textquoteright}s equations to the plasma momentum equation, FDTD models may also be constructed to account for the physics of electromagnetic wave propagation through magnetized ionospheric plasma.

Over the years, our research group has developed FDTD models of electromagnetic waves propagating globally around the world in the Earth-ionosphere waveguide [Simpson, Surveys in Geophysics, 30:2, 2009].\  Three generations of models have been developed:\  (1) a latitude-longitude grid; (2) a geodesic (hexagonal-pentagonal) grid; and (3) a Cartesian-based grid.\  These models have been applied to remote-sensing of localized ionospheric anomalies, remote-sensing of oil fields, geolocation, Schumann resonances, space weather effects on the operation of electric power grids, scintillation in the ionosphere, etc.\ \ 

In this presentation, we will provide an overview of our modeling capabilities, and we will also highlight a recent research activity relating to power line emissions (PLE) and power line harmonic radiation (PLHR) propagating into and through the ionosphere. For this project, the FDTD models are solve the full-vector Maxwell{\textquoteright}s equations coupled with the plasma momentum equation over a fully 3-D grid while considering the complex inhomogeneities of the ionospheric magnetized plasma (ducts, plasma bubbles, etc.). Our algorithm is highly efficient, allowing us to study the long timespans of the very low-frequency waveforms of interest as well as their long propagation paths from the ground to satellite altitudes.

Although we have not collaborated with Ham radio operators yet, we are very interested in doing so.\  Our models are ideally suited for investigating a number of interesting problems.\ 

}, author = {Apoorva Pedgaonkar and Jamesina Simpson} } @proceedings {693, title = {A Few Science Questions that HamSCI Can Help Address During the 2023 and 2024 Eclipses}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Solar eclipses are an exciting celestial event which can be used to study the terrestrial atmosphere and ionosphere systems. Locally, during a total solar eclipse, totality may only last a few minutes{\textemdash}and the times scales on which solar illumination decreases and then increases is much shorter that what is normally observed during sunrise and sunset. Additionally, on a larger, continental scale, the moon{\textquoteright}s umbra moves at supersonic velocities, tracing out the path of totality. These properties serve to act as an impulse in energy on the atmosphere and ionosphere, generating a wide variety of yet to be specified (or identified) responses in those systems.\ 

As an example of some compelling response effects, the fast depletion-replenishment of the bottomside ionosphere (the portion of the ionosphere that is below the F-region peak) often appears asymmetric{\textemdash}an observation that is not well understood. Therefore, one science question which can be addressed is: will the different geometries of the 2023 and 2024 eclipses as well as the fact that they are an annular and total eclipse, respectively, have a significant effect on the asymmetry of the bottomside evolution during the eclipse? Furthermore, efforts to model and replicate the observed effects of eclipses have significantly improved in recent years; however, observations of the atmosphere and ionosphere are still required to constrain, validate, and ultimately improve our theoretical understanding of these systems. Another eclipse science question which can be addressed is: how well will these models perform for the 2023 and 2024 eclipse and how can we quantify the response of the ionosphere during these events?\ 

Over the past few years, HamSCI has emerged at the forefront of passive remote sensing techniques in solar-terrestrial physics. This is evidenced by HamSCI{\textquoteright}s work using with HF timing signals and HF QSOs, show that both can be used to monitor the bottomside ionosphere on both regional and continental scales. The SEQP during the 2017 total solar eclipse was a resounding success, delivering high-impact and influential science results. Building upon that success, this technique may very well be a gamechanger for identifying and characterizing eclipse generated effects and phenomena during the upcoming 2023 and 2024 eclipses. The purpose of this presentation is to detail a few outstanding eclipse related science questions, and propose how HamSCI can lead the way in addressing them.

}, author = {Gareth W. Perry and Nathaniel A. Frissell and Joseph D. Huba} } @article {801, title = {Heliophysics and amateur radio: citizen science collaborations for atmospheric, ionospheric, and space physics research and operations}, journal = {Frontiers in Astronomy and Space Sciences}, volume = {10}, year = {2023}, month = {Apr-11-2024}, abstract = {

The amateur radio community is a global, highly engaged, and technical community with an intense interest in space weather, its underlying physics, and how it impacts radio communications. The large-scale observational capabilities of distributed instrumentation fielded by amateur radio operators and radio science enthusiasts offers a tremendous opportunity to advance the fields of heliophysics, radio science, and space weather. Well-established amateur radio networks like the RBN, WSPRNet, and PSKReporter already provide rich, ever-growing, long-term data of bottomside ionospheric observations. Up-and-coming purpose-built citizen science networks, and their associated novel instruments, offer opportunities for citizen scientists, professional researchers, and industry to field networks for specific science questions and operational needs. Here, we discuss the scientific and technical capabilities of the global amateur radio community, review methods of collaboration between the amateur radio and professional scientific community, and review recent peer-reviewed studies that have made use of amateur radio data and methods. Finally, we present recommendations submitted to the U.S. National Academy of Science Decadal Survey for Solar and Space Physics (Heliophysics) 2024{\textendash}2033 for using amateur radio to further advance heliophysics and for fostering deeper collaborations between the professional science and amateur radio communities. Technical recommendations include increasing support for distributed instrumentation fielded by amateur radio operators and citizen scientists, developing novel transmissions of RF signals that can be used in citizen science experiments, developing new amateur radio modes that simultaneously allow for communications and ionospheric sounding, and formally incorporating the amateur radio community and its observational assets into the Space Weather R2O2R framework. Collaborative recommendations include allocating resources for amateur radio citizen science research projects and activities, developing amateur radio research and educational activities in collaboration with leading organizations within the amateur radio community, facilitating communication and collegiality between professional researchers and amateurs, ensuring that proposed projects are of a mutual benefit to both the professional research and amateur radio communities, and working towards diverse, equitable, and inclusive communities.

}, doi = {10.3389/fspas.2023.1184171}, url = {https://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/fullhttps://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/full}, author = {Frissell, Nathaniel A. and Ackermann, John R. and Alexander, Jesse N. and Benedict, Robert L. and Blackwell, William C. and Boedicker, Rachel K. and Cerwin, Stephen A. and Collins, Kristina V. and Cowling, Scott H. and Deacon, Chris and Diehl, Devin M. and Di Mare, Francesca and Duffy, Timothy J. and Edson, Laura Brandt and Engelke, William D. and Farmer, James O. and Frissell, Rachel M. and Gerzoff, Robert B. and Gibbons, John and Griffiths, Gwyn and Holm, Sverre and Howell, Frank M. and Kaeppler, Stephen R. and Kavanagh, George and Kazdan, David and Kim, Hyomin and Larsen, David R. and Ledvina, Vincent E. and Liles, William and Lo, Sam and Lombardi, Michael A. and MacDonald, Elizabeth A. and Madey, Julius and McDermott, Thomas C. and McGaw, David G. and McGwier, Robert W. and Mikitin, Gary A. and Miller, Ethan S. and Mitchell, Cathryn and Montare, Aidan and Nguyen, Cuong D. and Nordberg, Peter N. and Perry, Gareth W. and Piccini, Gerard N. and Pozerski, Stanley W. and Reif, Robert H. and Rizzo, Jonathan D. and Robinett, Robert S. and Romanek, Veronica I. and Sami, Simal and Sanchez, Diego F. and Sarwar, Muhammad Shaaf and Schwartz, Jay A. and Serra, H. Lawrence and Silver, H. Ward and Skov, Tamitha Mulligan and Swartz, David A. and Themens, David R. and Tholley, Francis H. and West, Mary Lou and Wilcox, Ronald C. and Witten, David and Witvliet, Ben A. and Yadav, Nisha} } @proceedings {758, title = {Low-Cost Low-Power Ionosonde}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Ionosondes are a type of radar used to gather data about the height of the ionosphere. Typically, these systems can easily cost thousands of dollars and demand a lot of power. Using newer software defined radio technology, our goal is to develop a low cost, low power ionosonde.

}, author = {Gerard N. Piccini and Robert W. McGwier and Robert A. Spalletta and Majid Mokhtari and Nathaniel A. Frissell and Philip J. Erickson} } @proceedings {764, title = {Medium Scale Traveling Ionospheric Disturbances and their Connection to the Lower and Middle Atmosphere}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Nathaniel A. Frissell and Francis Tholley and V. Lynn Harvey and Sophie R. Phillips and Katrina Bossert and Sevag Derghazarian and Larisa Goncharenko and Richard Collins and Mary Lou West and Diego F. Sanchez and Gareth W. Perry and Robert B. Gerzoff and Philip J. Erickson and William D. Engelke and Nicholas Callahan and Lucas Underbakke and Travis Atkison and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {756, title = {A New Station for the W3USR University of Scranton Amateur Radio Club}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Tom Pisano and Nathaniel Frissell and Jeff DePolo and The W3USR University of Scranton Amateur Radio Club} } @proceedings {702, title = {The North Dakota Dual Aurora Camera Version 2.0 (NoDDAC2.0), a Platform for Citizen Science and a Use Case for Implementing Best Practices in Open Data and Collaboration}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The North Dakota Dual Aurora Camera (NoDDAC) is an interdisciplinary project created in collaboration with the University of North Dakota (UND), Live Aurora Network, and Aurorasaurus. Aurora cameras provide ground-truth visual data to aurora chasers and scientists but are sparse at midlatitudes (35-55{\textdegree}N). Deploying light-sensitive video and all-sky still cameras at these midlatitudes provides a valuable resource to aurora-chasing communities, as well as amateur radio operators in the auroral zone. In addition, NoDDAC data demonstrate scientific merit, as it can be correlated with radio and ionospheric propagation changes to investigate the connection between optical aurora and radio science. This project is unique; the practices of utilizing dual cameras with consumer-off-the-shelf equipment, emphasizing open data as a responsive community resource and promoting citizen science make NoDDAC an accessible resource benefiting multiple audiences. Since early 2021, NoDDAC has detected hundreds of auroras as well as notable events like STEVEs (Strong Thermal Emission Velocity Enhancement). NoDDAC is stationed at Martens Observatory (48.1{\textdegree}N, 97.6{\textdegree}W), which is operated by the UND Department of Physics and Astrophysics. Live Aurora Network provides weatherproof camera housings and their proprietary IPTimelapse software which allows for remote control of the cameras. This year we present NoDDAC2.0, the next evolution of NoDDAC funded by NASA{\textquoteright}s EPSCoR program. NoDDAC2.0 will upgrade the all-sky camera and feature a robust open-data platform to share aurora data with the public and scientists. We outline a strategy to increase the science utility of NoDDAC data, incorporating a citizen science project launching on the Zooniverse platform. We also present plans to integrate NoDDAC data into the AuroraX conjunction finder system so that satellite data can be easily correlated to aurora images. Most importantly, we are collaborating with the Nueta Hidatsa Sahnish College on the Fort Berthold Indian Reservation to install an independent aurora camera system in North Dakota. Not only does this represent a unique collaborative opportunity, but at a separation distance of 300 miles from Martens Observatory, this second camera will allow us to explore research questions relating to the precise location, height, and spatial extent of certain auroral phenomena.

}, author = {Timothy Young and Vincent Ledvina and Elizabeth MacDonald and Laura Brandt and Wayne Barkhouse and Alex Schultz and Cody Payne and Anne Mitchell and Kristian Haugen and Will Shearer and Kerry Hartman and Sasha Sillitti and Michael McCormack and Steve Collins} } @proceedings {757, title = {PyLap: An Open Source Python Interface to the PHaRLAP Ionospheric Raytracing Toolkit}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

PyLap is a Python interface to the ionospheric ray tracing toolkit PHaRLAP. The software allows users to generate accurate models of the ionosphere and ray tracing to make plots of radio propagation through the ionosphere. Not only does this software look, feel, and operate very similarly to how the MATLAB interface is currently used, it is also completely free alternative to the current MATLAB interface.

}, author = {Devin Diehl and Gerard Piccini and Alexander Calderon and Joshua Vega and William Liles and Nathaniel A. Frissell} } @proceedings {645, title = {An Algorithm for Determining the Timing of Components within the HamSCI-WWV/WWVH Scientific Test Signal}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Beginning in November 2021, WWV and WWVH radio stations have been broadcasting a test signal developed by a Ham Radio Science Citizen Investigation (HamSCI) working group to study what additional ionospheric measurements can be gleaned from the WWV/WWVH transmitter beyond carrier Doppler shift and time-of-flight of standard timing pulses. The signal consists of various individual components including tones, chirps, and Gaussian noise bursts [1]. Interested operators record the signal data at their location, providing researchers with the data naturally manipulated in many different ways [2]. This project seeks to precisely identify the timing of each signal component in the recorded data. The algorithm involves passing the data through various software filters to remove unwanted elements such as frequencies outside of range of interest, DC offset, and so on. Correlation is then performed between the recorded data and each original component to produce their timing. The performance of the algorithm itself is estimated by calculating the SNR of each received signal and the corresponding confidence interval of the algorithm. The results can help to explain the broken symmetry between the transmitted signal and the received signal.

References
[1] Lombardi. {\textquotedblleft}Radio Station WWV.{\textquotedblright} NIST, 16 Nov. 2021, https://www.nist.gov/pml/time-and-frequency-division/time-distribution/radio-station-wwv.
[2] Pamela.corey@nist.gov. {\textquotedblleft}WWV/WWVH Scientific Modulation Working Group.{\textquotedblright} NIST, 5 Nov. 2021, https://www.nist.gov/pml/time-and-frequency-division/time-services/wwvwwvh-scientific-modulation-working-group.

}, author = {Cuong Nguyen and Tyler Jordan and Joseph Tholley and Vaibhavi Patel} } @article {667, title = {Amateur Radio: An Integral Tool for Atmospheric, Ionospheric, and Space Physics Research and Operations}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.18632d86}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Michael Lombardi and Elizabeth MacDonald and Francesca Di Mare and Ethan S. Miller and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and David R. Themens and Mary Lou West} } @proceedings {628, title = {Climatology of Large Scale Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations of F-region ionospheric electron densities that can affect the range and quality of High Frequency (HF, 3-30 MHz) radio communications. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency radio signals propagating through the ionosphere. TIDs are of great interest scientifically because they are often associated with neutral Atmospheric Gravity Waves (AGWs) and can be used to advance understanding of atmosphere-ionosphere coupling. Large scale TIDs (LSTIDs) have periods of 30-180 min, horizontal phase velocities of 100 - 250 m/s, and horizontal wavelengths of over 1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). Current amateur radio observations are only able to detect LSTIDs. In this study, we present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, author = {Diego S. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and V. Lynn Harvey and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @article {670, title = {Fostering Collaborations with the Amateur Radio Community}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.09fe22b4}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and Timothy J. Duffy and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Elizabeth MacDonald and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and Tamitha Mulligan Skov and Mary Lou West} } @proceedings {637, title = {Potential Science Opportunities for HamSCI in Antarctica}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

The maturation and proliferation of passive radio receivers based on software defined radio principles and architecture herald a new era of radio remote sensing in solar-terrestrial physics. Antarctica is a region of interest for deploying HF radio receivers for many reasons. The significant offset of the geographic and magnetic poles allows one to study multiple terrestrial magnetosphere-ionosphere-thermosphere regions of interest, e.g., the polar, auroral, and sub-auroral zones, using ground-based instruments. Additionally, the significant snow and ice coverage in Antarctica is a strong absorber of HF radio waves. This severely mitigates intracontinental multi-hop propagation modes, which may be advantageous for geolocating geophysical features detected by HF radio techniques, thereby improving remote sensing performance. In this poster presentation, we will analyze a case of a QSO between two operators, captured by a receiver located at McMurdo Station in Antarctica. We will discuss the signal characteristics of each transmission and pay particularly close attention to how variations in the CW transmissions may be linked to geophysical processes occurring in the region at the time. The overarching goal of this presentation is to incite discussion on how existing and future passive HF receiving systems in Antarctica can leveraged to advance not only the art of radio but solar-terrestrial physics in Antarctica.

}, author = {Gareth W. Perry and Nathaniel A. Frissell} } @proceedings {622, title = {Properties and Drivers of Plasma Irregularities in the High-Latitude Ionosphere Computed using Novel Incoherent Scatter Radar Techniques}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

To provide new insights into the relationship between geomagnetic conditions and plasma irregularity scale-sizes, high-latitude irregularity spectra are computed using novel Incoherent Scatter Radar (ISR) techniques. This new technique leverages: 1) the ability of phased array Advanced Modular ISR (AMISR) technology to collect volumetric measurements of plasma density, 2) the slow F-region cross-field plasma diffusion at scales greater than 10 km, and 3) the high dip angle of geomagnetic field lines at high-latitudes. The resulting irregularity spectra are of a higher spatiotemporal resolution than has been previously possible with ISRs. Spatial structures as small as 20 km are resolved in less than two minutes (depending on the radar mode). In this work, we focus on Resolute Bay ISR observations operating in high-beam modes, such as the imaginglp mode. In addition to having an unprecedented view of the size and occurrence of irregularities as they traverse the polar cap, we find that near magnetic local noon the spectral power shifts to scales greater than 50 km, and from 15 to 5 magnetic local time the spectral power shifts to structures less than 50 km. This either reflects the role of polar cap convection in breaking down structures as they travel from the dayside ionosphere to the nightside, or the role of photoionization "smoothing" the dayside ionosphere. Additionally, during periods of enhanced geomagnetic conditions, such as periods with low AL indices, the spectral power shifts to structures 50 km and larger. This presentation will discuss these findings, as well as show seasonal variations.

}, author = {Lindsay V. Goodwin and Gareth W. Perry} } @proceedings {600, title = {SMART -- Expanding Array of Low Cost Magnetometers}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

The SMART (Surface Magnetic Assessment in Real Time) Network is a collection of 14 UCLA ground magnetometer systems across the US. Our main objective is to investigate outstanding questions in both travel-time and normal-mode magnetoseismologies. These detectors are very effective but expensive to build and maintain.\  SMART is a project to spread sensors to schools and perhaps private individuals. Broader impacts include training students in magnetic field measurements and geospace science. This provides outreach activities to schools hosting SMART systems and will provide SMART magnetometer data collected in the contiguous US to the public. 2020/2021 was time to investigate various solid state and coil systems to find detectors robust, simple, quiet and precise enough to give us reasonable measurements. Solid state and coil systems were built and compared. Finally, two systems met our requirements: RM3100 and FLC-100 coil sensors. Buried in the ground (away from temperature changes and movement) the two sensor systems compare favorably to the Falcon Search Coil system used here for the past 11 years. We will show comparative data in quiet and active times.\  We also discuss the various sensitivities of these sensors to electronic and temperature\  changes. We present a simple Raspberry Pi system that samples each of these detectors and uploads the data to google and adafuit.com clouds. We present details on construction and wiring of the system. Especially important is how to insulate and bury sensors to they see real magnet changes. Also presented will be estimated costs and availability of components. Our goal is to provide a simple and low-cost system for local measurement of the geomagnetic field.\  Additionally, the SMART team has restored many of the original UCLA sensors to operation and begun collection of data. As others build similar systems, we hope to bring many sensors into our array.

}, author = {Noel Petit and Peter Chi} } @proceedings {625, title = {Three Time-of-Flight Measurement Projects on a Common Hardware Platform}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Three undergraduate electrical engineering project groups at Case Western Reserve University are investigating distributed ionospheric sounding through time-of-flight measurements.\  All use GPS pulse-per-second signals for precise timing of received signals.\  Two use as their "radar signals of opportunity" LF, MF, and HF beacons from the US Department of Commerce National Institute of Science and Technology installations north of Fort Collins, Colorado and near Kekaha, Hawaii (radio stations WWVB, WWV, and WWVH).\  The third project modernizes the on-off telegraphy variant known as "coherent CW" (CCW). CCW uses amateur radio QSO or beacon transmissions as the measured signals.\  It facilitates Technician-licensee participation in active HF research and in keyboard-to-keyboard digital contacts, within FCC regulations.\  Using computed matched-filter techniques along the lines of FT8, CCW has a nearly optimal information-theoretic data recovery.\  With transmission or lookup of station locations, it can provide automated time of flight measurements while making a contact.\  The three projects use a common hardware platform for receiver or transceiver interfacing, involving synchronized analog data collection and front-end data processing with the Teensy variant of the Arduino platform.\  Teensy was chosen primarily for its sampling and computing speed. WWVB{\textquoteright}s signal can be sampled directly with the Teensy front-end and some data processing can done between sample acquisitions through timer interrupt programming.\  WWV/H second ticks delay measurements use inexpensive shortwave radio audio outputs, sampled and processed by the Teensy.\  The CCW sampling and matched filtering, plus synchronized Morse keying, are similarly done by the Teensy. Data presentation, user interface, and data uploading to repositories are done by minimal general purpose computers such as Raspberry Pi boards.\  We will present the common hardware and interrupt strategies along with a brief overview of the three projects.\  Comments and suggestions will be solicited, and of course participation in the projects is invited.\  The three projects are supported by a generous grant to the Case Amateur Radio Club W8EDU from ARDC.\  CARC is providing oversight of the projects and the projects use the club station as a laboratory facility.

}, author = {David Kazdan and John Gibbons and Kristina Collins and Maxwell Bauer and Evan Bender and Ryan Marks and Michael O{\textquoteright}Brien and Olivia O{\textquoteright}Brien and Gabriel Foss and Mari Pugliese and Alejandra Ramos and Carolina Whitaker} } @conference {586, title = {Amateur Radio Communications as a Novel Sensor of Large Scale Traveling Ionospheric Disturbances (Invited)}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Amateur (ham) radio high frequency (HF) communications are routinely observed by automated receiving systems on a quasi-global scale. As these signals are modulated by the ionosphere, it is possible to use these observations to remotely sense ionospheric dynamics and the coupled geospace environment. In this presentation, we demonstrate the use of these data to observe Large Scale Traveling Ionospheric Disturbances (LSTIDs), which are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected simultaneously over the continental United States in observations made by global HF amateur radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and discuss possible reasons why LSTIDs were observed in November but not May.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/822746}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Steven R. and Joshi, Dev Raj and Engelke, William and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {575, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=23773}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth W. and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Harvey, Lynn and Luetzelschwab, R. Carl} } @conference {582, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T ≈30-180 min, horizontal phase velocities vH≈ 100- 250 m/s, and horizontal wavelengths H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/1000724}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth and Harvey, Lynn and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {479, title = {e-POP RRI observations of the April 24, 2020 ARRL Frequency Measuring Test}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

One of the science objectives of the Radio Receiver Instrument (RRI) on the CAScade, Smallsat, and Ionospheric Polar Explorer/enhanced Polar Outflow Probe (CASSIOPE/e-POP) satellite is to study ionospheric influences on high frequency (HF) radio wave from low Earth orbit. RRI is made-up of 4, 3-m monopoles which can be electronically arranged into a crossed-dipole configuration.\  On April 24, 2020, RRI tuned to measure the ARRL frequency measuring test (FMT) on 40 m, and successfully recorded part of the {\textquotedblleft}call up{\textquotedblright} and all of the {\textquotedblleft}key down{\textquotedblright} segments of the test.\  The FMT provides a unique chance to study the effects of the ionospheric plasma on stable and reliable radio signals at frequencies that are close to the ionosphere{\textquoteright}s critical frequency, a frequency regime in which the influence of the ionospheric plasma on radio wave propagation conditions is most pronounced.\  In this presentation, we give preliminary results of our analysis of RRI{\textquoteright}s FMT measurements which include an examination of the FMT{\textquoteright}s Doppler characteristics, and the identification tell-tale signatures of ionospheric effects on the transmitted signal such as Faraday rotation and propagation mode delay.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=34-2B-1B-32-C8-FC-4A-0B-5B-51-B9-1D-10-4E-F2-7F}, author = {Brian O{\textquoteright}Donnell and Gareth Perry} } @conference {550, title = {HamSCI Campaign Co-Design (Panel Discussion)}, booktitle = {HamSCI Workshop 2021}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, organization = {HamSCI}, address = {Virtual}, author = {Kristina V. Collins and Nathaniel A. Frissell and Philip J. Erickson and Laura Brandt and Elizabeth MacDonald and Michael Black and Gareth Perry} } @proceedings {559, title = {HamSCI: Ham Radio Science Citizen Investigation}, year = {2021}, month = {09/2021}, publisher = {International Space Weather Action Team (ISWAT)}, address = {Virtual}, author = {Frissell, Nathaniel A. and Sanchez, Diego and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Gerzoff, Robert} } @conference {539, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. We present observations of TIDs made with a network of Ham Radio Science Citizen Investigation (HamSCI) Low-Cost Personal Space Weather Stations (PSWS) with nodes located in Pennsylvania, New Jersey, and Ohio. The TIDs were detected in the Doppler shifted carrier of the received signal from the 10 MHz WWV frequency and time standard station in Fort Collins, CO. Using a lagged cross correlation analysis, we demonstrate a method for determining TID wavelength, direction, and period using the collected WWV HF Doppler shifted data.

}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Clair Trop and Kristina Collins and Gareth Perry} } @conference {545, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {Annual (Summer) Eastern Conference}, year = {2021}, month = {07/2021}, publisher = {Society of Amateur Radio Astronomers (SARA)}, organization = {Society of Amateur Radio Astronomers (SARA)}, address = {Virtual}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. One way to detect TIDs is through the use of a Grape Personal Space Weather Station (PSWS). The Grape PSWS successfully detected TIDs in the Doppler shifted carrier of the received signal from the 10 MHz WWV frequency and time standard station in Fort Collins, CO. This paper will present an explanation of how the Grape PSWS was used to collect data, and how scientist can use this data to further investigate the ionosphere.

}, url = {https://rasdr.org/store/books/books/journals/proceedings-of-annual-conference}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Raj Joshi and William Liles and Claire C. Trop and Kristina V. Collins and Gareth W. Perry} } @proceedings {578, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in the WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/kVY3E3e--_I?t=3495}, author = {Romanek, Veronica I. and Frissell, Nathaniel A. and Joshi, Dev Raj and Liles, William and Trop, Claire and Collins, Kristina and Perry, Gareth W.} } @conference {580, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in the WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. We present observations of TIDs made with a network of Ham Radio Science Citizen Investigation (HamSCI) Low-Cost Personal Space Weather Stations (PSWS) with nodes located in Pennsylvania, New Jersey, and Ohio. The TIDs were detected in the Doppler shifted carrier of the received signal from the WWV frequency and time standard station near Fort Collins, CO. Using a lagged cross correlation analysis, we demonstrate a method for determining TID wavelength, direction, and period using the collected WWV HF Doppler shifted data.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/888443}, author = {Romanek, Veronica I. and Frissell, Nathaniel A. and Joshi, Dev Raj and Liles, William and Trop, Clair and Collins, Kristina and Perry, Gareth W.} } @proceedings {495, title = {K2MFF: Nearly a Century of Advancing the Radio Art at NJIT}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The New Jersey Institute of Technology Amateur Radio Club (NJITARC), K2MFF, has been an active part of the NJIT community for nearly a century.\  K2MFF has been a diligent community member, volunteering in such large-scale events as the New York City Marathon for over 30 years.\  Not only that, K2MFF, has been a fertile ground for developing young technical talent and advances in the radio art.\  Indeed, K2MFF has been a supporter and contributor to the HamSCI effort since its inception.\  In this presentation, we will offer a brief history of K2MFF, and discuss the current status and activities of the club.\  We will also offer some prognosis of the club{\textquoteright}s future directions.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=6A-73-A8-1F-B3-F9-DE-00-42-92-9A-F7-6B-59-C4-ED}, author = {Gareth W. Perry and F. Chu and Peter Teklinski} } @conference {537, title = {Observing Large Scale Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Climatology with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications. LSTIDs create concavities in the ionospheric electron density profile that move horizontally with the LSTID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. This phenomena manifests as quasi-periodic variations in contact ranges in HF amateur radio communications recorded by automated monitoring systems such as RBN and WSPRNet. In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity as well as using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector, season, and geomagnetic activity level. Connections to neutral atmospheric sources are also explored.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {465, title = {Observing Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Validation and Climatology}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T\ \approx30-180\ min, horizontal phase velocities v_H\approx‍100-‍250 m/s, and horizontal wavelengths \lambda_H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). First in this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a case study showing consistency in LSTID signatures in RBN and WSPRNet are also present in Super Dual Auroral Radar Network (SuperDARN), Global Navigation Satellite System (GNSS), and ionosonde measurements. Then, we present a climatology of LSTID activity as well as\  using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {496, title = {The Oldest Cadet Club, Today: W2KGY}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Although the Cadet Amateur Radio Club, callsign W2KGY, boasts the title of {\textquoteleft}Oldest Cadet Club{\textquoteright} since its founding in 1926, it leads cutting-edge innovation on radioscience and sport. The club develops technically adept leaders of character trained on military equipment while maintaining a developmental culture from its amateur background. This poster showcases past accomplishments of the club and presents its future plans as a cornerstone of electromagnetic warfare training for the Corps of Cadets. Further, the poster demonstrates the club{\textquoteright}s usefulness to the academy as a research testbed for satellite operation and propagation studies.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=D0-F7-C3-77-98-1D-B7-4E-B5-9A-70-5F-4A-2E-07-3D}, author = {Nolan Pearce and Pat McGurrin} } @proceedings {476, title = {Simulation and Comparison of Weak-Signal VHF Propagation}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Space weather{\textquoteright}s intense variance has a seemingly random effect on radio propagation in the Very High Frequency (VHF) range. Key models are built to analyze and estimate performance of wireless systems in these weak-signal propagation mediums. Chiefly, meteor burst communication, auroral propagation, and earth-moon-earth communication models are built and simulated on MATLAB. The results are confirmed through experimental testing and data comparison. Overall, modeling of these space weather events proves immense usefulness in predicting effectiveness of radio equipment through these weak-signal modes.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=0B-3C-92-BC-7A-A2-35-0C-0B-52-1C-29-5A-03-4F-46}, author = {Nolan Pearce and Kate Duncan} } @proceedings {490, title = {SMART Ground Based Magnetometer Array - an Initial Look}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Augsburg University has been involved with ground based magnetometers for the past 25 or so years. These magnetometers monitor the earth{\textquoteright}s magnetic field and its changes as the ionospheric field is perturbed by solar wind and other influences. As part of an array of detectors, we monitor the fields here in Minnesota with a flux gate magnetometer as part of the UCLA "Smart" array. This detector is sensitive to about 10 nano tesla and located in an electronically quiet hillside.\ 

In addition, in the past few years a number of solid state detectors have been integrated into easy to monitor circuits and mated with the Raspberry Pi microcomputer. Most of these cost a few dollars and if placed away from metalic influence can give reasonable measurements -- especially of large changes in local field. Specifically, we will show the output from the LIS3MDL magnetometer compared to a high cost fluxgate system. Also discussed are the GY-511(LSM303) and GY-271 (HMC5883L) Compass/Magnetometers.\ 

These data are passed to io.adafruit.com a cloud storage/plotting system that provides access to plots and data for other to monitor. Cloud services allow many users to access a wide network of data without any programming or management of the cloud. With the onset of the next solar cycle, home monitors will become useful in propagation estimates.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=D1-53-61-0E-39-F6-CA-23-13-5A-67-79-FF-84-94-E0}, author = {Noel J. Petit and Peter Chi} } @conference {542, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in simultaneously over the continental United States in observations made by global High Frequency (HF) amateur (ham) radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and that seasonal neutral atmospheric conditions may play a role in preventing AGW propagation in May but not in November.

}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Gareth W. Perry and Dev Joshi and William D. Engelke and Evan G. Thomas and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {555, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {05/2021}, publisher = {SANSA}, address = {Virtual}, url = {https://www.sansa.org.za/events-outreach/superdarn-workshop-2021/}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {574, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=22608}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @conference {405, title = {Direction Finding: Analog and Digital Applications (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Amateur radio encompasses the building of hardware, the programming of different communications devices, and the integration of hardware and software. One popular amateur pastime, radio direction finding, requires a fair amount of technical knowledge to include antenna design and radio wave propagation in the VHF radio band. Participants use specialized directional antennas to find a bearing for an unknown signal. An intense understanding of antenna radiation patterns can be used to accurately identify the source of this signal. Simulation on computer programs through test equipment helps hobbyists fully understand the characteristics of their direction finding devices. However, direction finding can be approached from the electronic realm as well as the physical realm. Instead of just directional antennas, one can utilize Digital Signal Processing (DSP) with software-defined radios to locate and identify unknown signals. Programs such as Matlab and GNURadio combined with hardware such as the KerberosSDR and HackRF fully utilize this avenue of signals intelligence. The dichotomy between {\textquotedblleft}physical{\textquotedblright} direction finding and digital signal processing provides an interesting argument for use of one over another. While antenna-focused direction finding relies on vast technical knowledge of propagation and gain, computer- based direction finding similarly requires computational knowledge with various signals and mathematical techniques. In addition, the two techniques serve almost divided purposes: while analog direction finding can locate a signal real-time, DSP can be used to deconstruct and decode signals after their interception. One technique does not outweigh the other, as both have different use cases and applicability. This presentation will outline the basic approach to each avenue of direction finding and the advantages each technique holds. Hobbyists should learn from both techniques of direction finding to gain applicable skills in electromagnetic wave theory.

}, author = {Nolan Pearce} } @conference {390, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications
and associated Joule heating.

}, author = {D. Sanchez and N. A. Frissell and G. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker} } @conference {425, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, GNSS TEC, and Ionosondes}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {D. F. Sanchez and N. A. Frissell and G. W. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker and R. C. Luetzelschawb} } @conference {399, title = {Novel methods for characterizing ionospheric irregularities in the high-latitude ionosphere (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Plasma structuring in the high-latitude ionosphere impacts over-the-horizon radio communication and global navigation systems, and is an important space weather effect. Therefore, characterizing the formation and evolution of these structures is critically important. It is useful to create {\textquoteleft}{\textquoteleft}irregularity spectra", which quantify the sizes of plasma structures in the high-latitude ionosphere.\ \ The shape of the spectra (and other characteristics) can provide insight into the source of the irregularities. From this information it is then possible to forecast the occurrence of irregularities and predict their impact on radio wave propagation and communications. We are able to compute irregularity spectra by leveraging the phased array design of several incoherent scatter radars (ISRs), and using some unique properties of the F-region plasma at high-latitudes.\ \ In this presentation we will describe how we develop and apply a novel technique for ISR measurements to resolve high-latitude ionospheric irregularity spectra at a finer resolution than has been previously possible with ground-based instruments. We will motivate the newly developed ISR technique, describe its methodology, and provide some first results demonstrating its effectiveness. This technique will enable future studies that will directly link high-latitude ionospheric plasma structure drivers to their impact on radio wave communications.

}, author = {Lindsay V. Goodwin and Gareth Perry} } @conference {382, title = {Update on the Golden Ears Project}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The Radio Receiver Instrument (RRI), part of the Enhanced Polar Outflow Probe (e-POP) science payload on the Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE) spacecraft, has recorded continuous wave (CW; Morse code) transmissions during the American Radio Relay League (ARRL) Field Day exercises since 2015. Perry et al. (2018) demonstrated the value of such transmissions to radio science. By identifying a handful of hams in the RRI data collected during the 2015 Field Day and inputting their transmitting locations into a high frequency (HF) ray tracing model, Perry et al. were able to accurately estimate foF2 over a portion of the midwestern United States. They were also able to diagnose the periodic fading in the amplitude of one ham{\textquoteright}s transmission as a multipath propagation effect unique to transionospheric propagation.

One lesson from the Perry et al. analysis was that decoding the transmissions using CW {\textquotedblleft}skimmers{\textquotedblright}, software capable of decoding large bands of CW signal, was not feasible with the RRI data. This is likely due to the fact that the signals disperse and degrade as they transit from the ground, through the ionosphere, and up to the spacecraft. As a result, the Perry et al. transmissions had to be decoded aurally by the article{\textquoteright}s co-authors. Since 2015, RRI has collected several hours of ARRL Field Day transmissions, necessitating a more organized decoding effort, rather that the ad hoc methodology employed thus far.

Accordingly, the {\textquotedblleft}Golden Ears Project{\textquotedblright} was initiated following the RRI operations for the 2019 ARRL Field Day. The goal of the project is straightforward: use members of the ham community with a distinct aptitude for aurally decoding CW signals (i.e., individuals with {\textquotedblleft}Golden Ears{\textquotedblright}) to decode data collected by RRI in thorough and organized way. In this presentation we will disseminate the first project{\textquoteright}s first results from 2019 Field Day operations. We will describe the experimental setup, methodology used to prepare the data from the decoders, discuss their results, and outline the future directions of the project.

Perry, G. W., Frissell, N. A., Miller, E. S., Moses, M., Shovkoplyas, A., Howarth, A. D., \& Yau, A. W. (2018). Citizen Radio Science: An Analysis of Amateur Radio Transmissions With e-POP RRI. Radio Science, 933{\textendash}947. https://doi.org/10.1029/2017RS006496

}, author = {G. Perry and P. J. Erickson and B. D. Blain and R. Reif and N. A. Frissell} } @conference {339, title = {Contesting with FT4 - Issues and Opportunities Going Forward}, booktitle = {Dayton Hamvention}, year = {2019}, month = {05/2019}, publisher = {Ham Radio 2.0}, organization = {Ham Radio 2.0}, address = {Xenia, OH}, author = {John Pescatore} } @conference {300, title = {Digital Mobile Radio Support of High Altitude Balloons for a 2017 Total Solar Eclipse Cloud Formation Experiment}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Edge of Space Sciences (EOSS, eoss.org) is a Denver, Colorado based non-profit organization that promotes science and education by exploring frontiers in amateur radio and high altitude balloons. Two years prior to the total eclipse of the sun (21AUG17) we were approached by Colorado University Boulder Space Grant Consortium \& NASA about flying a pair of balloons with high resolution cameras for the eclipse. They wanted a specific altitude (85,000 foot) at the total eclipse for their cameras which was going to occur in Southeastern Wyoming. They were looking for cloud formation during the eclipse and this was coordinated with three mobile Doppler radar trucks. We did a survey of the predicted landing zone (Southeastern Wyoming/Western Nebraska) and found that there was little to no cellular service and zero amateur repeater coverage. Terrain considerations negated the use of 2M or UHF simplex and HF didn{\textquoteright}t have the right propagation. We designed a 4 site Motorola Digital Mobile Radio (DMR) system using IPSite connect with a combination of microwave and VSAT backhaul. We coordinated 4 sets of Emergency Special Event UHF DMR repeater frequencies from the Wyoming Frequency coordinator (W7QQA, Leonard Pearce). We located 4 sites and negotiated with the owners (including the use of the City of Torrington, Wyoming water tower) and ran Longley Rice coverage studies from each location. We rented and programmed 10 Motorola 4550 mobiles and installed them in the tracking and recovery crew vehicles and trained then on how to use them. We programmed up the mobiles with roaming lists and the system {\textquotedblleft}pinged{\textquotedblright} every 15 seconds (1/4 mile at 60 MPH). All the tracking and recovery teams had to do was push the PTT and wait for the {\textquotedblleft}go tone{\textquotedblright}. We used the second time slot to communicate with the Goshen County Sheriff Department who{\textquoteright}s main 911 dispatcher during the eclipse was a Ham for use in the event there was a public safety issue in a location without cell coverage. We built and tested all of the repeaters and duplexers and double conversion UPS and kitted them up together with the feed lines and antennas. One site used Telewave ANT450D6 antenna set to cardioid pattern to put the RF energy where we needed it. Our Comms team of 6 installed the system over one weekend a week before the event. We did a {\textquotedblleft}drive test{\textquotedblright} and determined that our Longley-Rice pattern studies were very conservative and the system coverage significantly exceeded the predicted coverage. The system covered more than 7,600 square miles of Southeastern Wyoming.

}, author = {Michael Pappas} } @conference {361, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/581488}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Evan Markowitz and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @conference {313, title = {A Research Quality, Low Power and Cost Magnetometer Package for use in Citizen Science (Demonstration)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

A high precision low cost magnetometer package combining GPS time keeping, data logging, real time graphing, and wifi data distribution is under development by the Moldwin Magnetics Laboratory at the University of Michigan. The prototype collects data for use in geomagnetic sensing. The system includes a Solar panel, a 12V lead acid battery, and a charge controller. All electronics are enclosed in a weatherproof plastic case, except for the magnetometer, which is housed separately to reduce noise. Data is processed by a raspberry pi and displayed on a color HDMI LCD screen. Our goal of keeping costs low helps distribute the system to citizens to form a network of magnetometers to better monitor our environment.

}, author = {Mark Moldwin and Kit Ng and Jacob Thoma and Leonardo Regoli and Maya Pandya} } @conference {325, title = {Sounding the Ionosphere with Signals of Opportunity in the High-Frequency (HF) Band}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

The explosion of commercial off-the-shelf (COTS) education- and consumer-grade hardware supporting software-defined radio (SDR) over the past two decades has revolutionized many aspects of radio science, bringing the cost and calibration of traditionally complex receiver hardware within the grasp of even advanced amateur experimenters. Transmission has now become the limiter of access in many cases, particularly through spectrum management and licensing considerations. Fortunately, several classes of signals endemic to the HF band lend themselves to processing for ionospheric characteristics: time and frequency standard broadcasters, surface-wave oceanographic radars, amateur radio transmissions, and ionospheric sounders.

This presentation is a tour of these signals of opportunity and techniques for collecting and processing them into ionospheric characteristics, with emphasis on distributed receivers collecting on a small number (four or fewer) of coherent channels. Receiving techniques will be discussed for near-vertical ({\textquotedblleft}quasi-vertical{\textquotedblright}) incidence skywave (NVIS or QVI), long-distance oblique soundings, and transionospheric sounding. Soundings will be demonstrated from space-based, ground-based, and maritime platforms.

Binary, Doppler, delay, cone angle of arrival, and polarization observations will be exploited, depending on the signal type and capability of the collector. Each of these techniques conveys different, but not always {\textquotedblleft}orthogonal,{\textquotedblright} information about the ionospheric skywave channel. The information content of each datum will be discussed with respect to the implications for inverting the local or regional ionosphere from the observations. More importantly than inverting the full ionosphere, some of these techniques are sensitive indicators of ionospheric irregularities, structures, and instabilities, that might otherwise be difficult to study due to limited geographic coverage with larger, more exquisite instrumentation.

}, author = {Ethan S. Miller and Gary S. Bust and Gareth W. Perry and Stephen R. Kaeppler and Juha Vierinen and Nathaniel A. Frissell and A. A. Knuth and Philip J. Erickson and Romina Nikoukar and Alexander T. Chartier and P. Santos and C. Brum and J. T. Fentzke and T. R. Hanley and Andrew J. Gerrard} } @article {255, title = {Citizen radio science: an analysis of Amateur Radio transmissions with e-POP RRI}, journal = {Radio Science}, year = {2018}, abstract = {

We report the results of a radio science experiment involving citizen scientists conducted on 28 June 2015, in which the Radio Receiver Instrument (RRI) on the Enhanced Polar Outflow Probe (e-POP) tuned-in to the 40 and 80 m Ham Radio bands during the 2015 American Radio Relay League (ARRL) Field Day. We have aurally decoded the Morse coded call signs of 14 Hams (amateur operators) from RRI{\textquoteright}s data to help ascertain their locations during the experiment. Through careful analysis of the Hams{\textquoteright} transmissions, and with the aid of ray tracing tools, we have identified two notable magnetoionic effects in the received signals: plasma cutoff and single-mode fading. The signature of the former effect appeared approximately 30 seconds into the experiment, with the sudden cessation of signals received by RRI despite measurements from a network of ground-based receivers showing that the Hams{\textquoteright} transmissions were unabated throughout the experiment. The latter effect, single-mode fading, was detected as a double-peak modulation on the individual {\textquotedblleft}dots{\textquotedblright} and {\textquotedblleft}dashes{\textquotedblright} of one the Ham{\textquoteright}s Morse coded transmissions. We show that the modulation in the Ham{\textquoteright}s signal agrees with expected fading rate for single-mode fading. The results of this experiment demonstrate that Ham Radio transmissions are a valuable tool for studying radio wave propagation and remotely sensing the ionosphere. The analysis and results provide a basis for future collaborations in radio science between traditional researchers in academia and industry, and citizen scientists in which novel and compelling experiments can be performed.

}, keywords = {Citizen Science, ionosphere, Radio Propagation, Radio Science, Satellite}, doi = {10.1029/2017RS006496}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2017RS006496}, author = {Perry, G. W. and Frissell, N. A. and Miller, E. S. and Moses, M. and Shovkoplyas, A. and Howarth, A. D. and Yau, A. W.} } @conference {176, title = {Fitting Ionospheric Models Using Real-Time HF Amateur Radio Observations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {J. D. Katz and N. A. Frissell and J. S. Vega and A. J. Gerrard and R. B. Gerzoff and P. J. Erickson and E. S. Miller and M. L. Moses and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas} } @conference {175, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppller and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {174, title = {HamSCI: The Ham Radio Science Citizen Investigation (Banquet Presentation)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and J. Dzekevich and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppler and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {173, title = {Ionospheric Simulations of the 2017 Solar Eclipse QSO Party}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and M. L. Moses and G. D. Earle and S. W. Gunning and A. J. Gerrard and E. S. Miller and M. L. West and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas and H. W. Silver} } @conference {143, title = {HamSCI: The Ham Radio Science Citizen Investigation}, booktitle = {Fall 2016 American Geophysical Union}, year = {2016}, month = {12/2016}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco}, abstract = {

Amateur (or {\textquotedblleft}ham{\textquotedblright}) radio operators are individuals with a non-pecuniary interest in radio technology, engineering, communications, science, and public service. They are licensed by their national governments to transmit on\ amateur radio frequencies. In many jurisdictions, there is no age requirement for a ham radio license, and operators from diverse backgrounds participate. There are more than 740,000 hams in the US, and over 3 million (estimated)\ worldwide. Many amateur communications are conducted using transionospheric links and thus affected by space weather and ionospheric processes. Recent technological advances have enabled the development of\ automated ham radio observation networks (e.g. the Reverse Beacon Network,\ www.reversebeacon.net) and specialized operating modes for the study of weak-signal propagation. The data from these networks have been\ shown to be useful for the study of ionospheric processes. In order to connect professional researchers with the volunteer-based ham radio community, HamSCI (Ham Radio Science Citizen Investigation,\ www.hamsci.org) has\ been established. HamSCI is a platform for publicizing and promoting projects that are consistent with the following objectives: (1) Advance scientific research and understanding through amateur radio activities. (2) Encourage\ the development of new technologies to support this research. (3) Provide educational opportunities for the amateur community and the general public. HamSCI researchers are working with the American Radio Relay League\ (ARRL,\ www.arrl.org) to publicize these objectives and recruit interested hams. The ARRL is the US national organization for amateur radio with a membership of over 170,000 and a monthly magazine, QST. HamSCI is\ currently preparing to support ionospheric research connected to the 21 Aug 2017 Total Solar Eclipse by expanding coverage of the Reverse Beacon Network and organizing a large-scale ham radio operating event ({\textquotedblleft}QSO\ Party{\textquotedblright}) to generate data during the eclipse.

}, url = {http://hamsci.org/sites/default/files/publications/2016_AGU_Frissell_HamSCI.pdf}, author = {Nathaniel A. Frissell and Magdalina L. Moses and Gregory Earle and Robert W. McGwier and Ethan S. Miller and Steven R. Kaeppler and H. Ward Silver and Felipe Ceglia and David Pascoe and Nicholas Sinanis and Peter Smith and Richard Williams and Alex Shovkoplyas and Andrew J. Gerrard} } @conference {51, title = {e-POP Radio Science Using Amateur Radio Transmissions}, booktitle = {Fall AGU - Poster Presentation}, year = {2015}, month = {12/2015}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

A major component of the enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument (RRI) mission is to utilize artificially generated radio emissions to study High Frequency (HF) radio wave propagation in the ionosphere. In the North American and European sectors, communications between amateur radio operators are a persistent and abundant source source of HF transmissions. We present the results of HF radio wave propagation experiments using amateur radio transmissions as an HF source for e-POP RRI. We detail how a distributed and autonomously operated amateur radio network can be leveraged to study HF radio wave propagation as well as the structuring and dynamics of the ionosphere over a large geographic region. In one case, the sudden disappearance of nearly two-dozen amateur radio HF sources located in the midwestern United States was used to detect a enhancement in foF2 in that same region. We compare our results to those from other more conventional radio instruments and models of the ionosphere to demonstrate the scientific merit of incorporating amateur radio networks for radio science at HF.

}, author = {Nathaniel A. Frissell and Gareth Perry and Ethan S. Miller and Alex Shovkoplyas and Magdalina Moses and H. James and Andrew Yau} } @article {45, title = {Ionospheric Sounding Using Real-Time Amateur Radio Reporting Networks}, journal = {Space Weather}, volume = {12}, year = {2014}, pages = {651{\textendash}656}, abstract = {

Amateur radio reporting networks, such as the Reverse Beacon Network (RBN), PSKReporter, and the Weak Signal Propagation Network, are powerful tools for remote sensing the ionosphere. These voluntarily constructed and operated networks provide real-time and archival data that could be used for space weather operations, forecasting, and research. The potential exists for the study of both global and localized effects. The capability of one such network to detect space weather disturbances is demonstrated by examining the impacts on RBN-observed HF propagation paths of an X2.9 class solar flare detected by the GOES 15 satellite. Prior to the solar flare, the RBN observed strong HF propagation conditions between multiple continents, primarily Europe, North America, and South America. Immediately following the GOES 15 detection of the solar flare, the number of reported global RBN propagation paths dropped to less than 35\% that of prior observations. After the flare, the RBN showed the gradual recovery of HF propagation conditions.

}, keywords = {Instruments and techniques, ionosphere, Ionospheric effects on radio waves, Solar effects}, issn = {1542-7390}, doi = {10.1002/2014SW001132}, url = {http://hamsci.org/sites/default/files/publications/2014_SpaceWeather_Frissell_RBN.pdf}, author = {Frissell, N. A. and Miller, E. S. and Kaeppler, S. R. and Ceglia, F. and Pascoe, D. and Sinanis, N. and Smith, P. and Williams, R. and Shovkoplyas, A.} }