@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 {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 {940, title = {Effect of the equatorial plasma bubbles on amateur radio communication: Full-wave simulation Study}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present the impact of equatorial plasma bubbles (EPB) on high-frequency (HF) wave propagation, such as amateur (ham) radio communications, in the ionosphere. Ionospheric density irregularities occur over a wide range of latitudes from the equator to the polar region and local times. Many numerical efforts have been made to study wave propagation in the ionosphere; however, several challenges arise in modeling the propagation of HF waves. For example, the wavelength of radio waves in the ionosphere is much shorter than the ray path and the thickness of the ionosphere; thus, simulating these waves requires high-performance computing resources. This challenge is one reason why previous research has predominantly focused on ray tracing and analytical calculations. For such reasons, the properties of HF waves{\textemdash}such as reflection, refraction, scattering, and scintillation{\textemdash}are not fully understood in the context of density irregularities. This presentation introduces the state-of-the-art full-wave simulation code, Petra-M. \ We then conduct numerical examinations of how the EPB affects HF wave propagation. We utilize density irregularity structures, such as EPBs, derived from other simulations as background ionospheric density structures. Due to the small-scale density fluctuations in the EPB, HF waves can reach higher altitudes with scattering and trapping in the density structure. Mode conversion from the incoming HF wave to the electrostatic waves, which are localized waves in the ionosphere, also occurs. Such effects can lead to failed wave detection at the receiver since the wave power reaches a broader area near the receiver due to scattering, and wave power can decrease because of the wave mode conversion.

}, author = {Eun-Hwa Kim and S. Shiraiwa and J. R. Johnson and J. Huba and K Hozumi and S. Wing and N. Bertelli} } @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 {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 {926, title = {Interim Findings of the HamSCI DASI2 HF Antenna Project}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

An ad hoc HamSCI DASI2 Antenna Group was tasked in late 2024 with evaluation of antenna options for the DASI2 grant. We present the the materials, methods, and criteria we have so far developed to accomplish this along with preliminary results. \ Antenna systems under consideration include DXE-RSEAV-1FVI, N6GN SAS, LZ1AQ loop dipole, and others. \ The materials include key elements already intended for use in the grant -- the RX888-SDR and software such as the KA9Q-Radio system, the KA9Q-Web spectrum display, WSPRDAEMON, and spot and noise reception reports to wspr.net, wsprdaemon.org, and pskreporter. \ The methods leverage ITU noise figures, known broadcast station locations, significant recent improvements in the spectrum display, and analysis of the local site. \ The criteria so far include antenna performance metrics, site evaluation, ease of deployment, support needs, and cost. This effort will enable us to provide good quality information, some of which we present, for selecting an appropriate antenna for the grant. \ However, the effort to solve this particular task has also demonstrated the general utility of these tools and methods for the amateur radio community. \ A view of the entire HF spectrum enable at-a-glance assessments that can help one more effectively identify and solve problems and optimize reception given the natural limitations of one{\textquoteright}s site. \ One can see recognizable patterns suggesting local and propagated noise, overmodulation, aliasing, inadequate front-end gain, ground loops, and more. \ One can compare two (or more) antennas or one antenna with itself at different sites or orientations, the effects of feed-line placement, interactions with nearby structures or foliage, and more. \ These efforts will inform the choice of an antenna to use for the DASI2 grant but can prove immediately useful for all hams and scientists in understanding and optimizing their receiving systems.

}, author = {Michael Hauan and Glenn Elmore and Rob Robinett and Gwyn Griffiths and Dve Witten and Ulli Grunow and Clint Turner} } @proceedings {951, title = {Monitoring tropospheric propagation at 24 GHz: A pilot study}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

HamSCI{\textquoteright}s upper atmosphere and space physics focus has drawn on ionospheric observations by hams using protocols including WSPR, and precision measurements of transmitters WWV and CHU with the information gathered into databases. Such techniques are applicable to other amateur radio fields to advance understanding of propagation. As an example, we describe a UK pilot system for monitoring tropospheric propagation at 24 GHz. The transmitter (JO01mt22 12 m ASL) on 24.048945 GHz has a GPS disciplined oscillator and outputs 7 W ERP to an omnidirectional antenna. Transmissions alternate each minute between WSJT-X{\textquoteright}s JT4G sub-mode and a carrier with CW identification. The 53 km test path over the Thames Estuary glances the sea surface to a receiver (JO01qj81 80 m ASL). At the receiver a masthead down-converter to 400 MHz IF connects to a Raspberry Pi controlled SDR running OpenWebRX. The pilot SDR, an RTL-dongle, is to be replaced by an Airspy R2. The data monitoring software, based on early WsprDaemon, processes WSJT-X wav files. It logs basic data of callsign, SNR and frequency from JT4G and signal and noise levels from carrier-only intervals. SNR derived from the carrier shows greater resolution and dynamic range than from JT4G. Measurements of frequency with lower scatter are obtained from cross-correlating the JT4G signal with its sync vector, finding the peaks via continuous wavelet transform then interpolation.\  Data on environment variables that may affect propagation is collected from a lightship, including air and sea temperature, relative and absolute humidity and wave height. Rain rate is from a shore station near the transmitter. Radio and environmental data go to a database with a Grafana dashboard for visualisation. Encouraging semi-quantitative effects of changes in the environment on propagation have been observed. These include: signal dropout at absolute humidity above 8 g/m3; increased variance of frequency with waveheights above 1 m; and signal level reducing gradually by 8 dB during the passage of a cold front with a band of rain up to 1 mm/hour.

}, author = {Gwyn Griffiths and John Worsnop} } @proceedings {947, title = {The NRAO Exploring the EMS/Ham Radio Project: The Way Ahead}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Abstract: The National Radio Astronomy Observatory (NRAO) Ham Radio Project "Exploring the Electromagnetic Spectrum (EMS)" is an Amateur Radio Digital Communications (ARDC)-funded project that is designed to help young people{\textemdash}especially those from communities not traditionally involved in radio astronomy or amateur radio{\textemdash}by exposing them to both interrelated fields. The 40-week program accomplishes this goal by encouraging learners to build self-sustaining STEM identities and communities that center their governance structures, ways of knowing, and meaning-making, as well as creating a scalable, open-source licensed curriculum on the SuperKnova Moodle Learning Management System (LMS). The project{\textquoteright}s mission, connecting and acquainting learners with the development of wireless technology and radio astronomy while helping them achieve amateur radio licensure, continues considering recent retrenchment of programs designed to include historically excluded People of Culture (PoC). Lessons learned from this program as well as the way ahead will be described.

}, author = {Jesse Alexander and Alia Wafford} } @proceedings {945, title = {Predictive Implications of Space Weather on Quantum Network Functionality}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Quantum communication networks leverage the unique quantum-mechanical properties of photons to enable secure communications and advanced sensing capabilities. Precision distributed timing and polarization compensation, which must be maintained within stringent tolerances, are critical for enabling quantum network protocols such as Bell state distribution. Previous studies have demonstrated that environmental factors significantly impact network performance in these critical areas. Motivated by unusual observations during the 2024 total solar eclipse on DC-QNet---a quantum network testbed in the national capital region---this research aims to quantify the effect of space weather phenomena on quantum network performance. In this preliminary study, we analyze daily geomagnetic data, 10.7 cm radio flux, and sunspot numbers as predictors in correlation and regression analyses. These analyses use daily aggregated data related to White Rabbit time synchronization errors from several DC-QNet experiments. Initial results suggest that some space weather indicators, such as radio flux and sunspot numbers, exhibit moderate correlation with time synchronization errors over a single, predominantly aerial fiber optic link. However, higher-resolution magnetometer and X-ray flux data show negligible correlation, even after various data transformations. Additionally, model performance is weak across the board, with general linear model assumptions violated in most cases. These findings demonstrate the complexity of linking space weather fluctuations to quantum network performance and suggest that other environmental or operational factors may play a more significant role.

}, author = {Brett Martin and Douglas Hodson and Michael Grimalia and Torrey Wagner} } @proceedings {956, title = {Understanding HamSCI Magnetometers Measurements and Observations}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Measurements and observations are important to any project. Understanding where the measurements came from and how they are collected is vital. In this presentation, we will aim to describe what a magnetometer is, how it works, and what information it can tell us about space weather/physics. We will focus on what measurements and observations we can collect from the magnetometers{\textendash} specifically HamSCI magnetometers as various magnetometers will have different capabilities. Furthermore, we will outline an experimental procedure to help the user better understand the collected measurements and observations from the HamSCI magnetometer. We will focus on some questions such as, what can HamSCI magnetometer measurements and observations tell us? How do we know good vs bad HamSCI magnetometer data? Do we need to calibrate the measurements and observations of the HamSCI magnetometer data? Why do we collect three components of the magnetic field yet primarily use only the horizontal component. How does the internal magnetic field of the Earth impact the magnetic field around the Earth? Where can we see and access the raw measurements and observations from the HamSCI magnetometers? How are the measurements and observations displayed? By answering these questions and outlining the experiment(s), we hope to provide an education guide to help users better understand how the HamSCI magnetometers record observations and measurements and what insight they can give us into better understanding various space weather/physics phenomena.

}, author = {Rachel Frissell and Nathaniel Frissell and Majid Mokhtari and David Witten and Hyomin Kim} } @proceedings {820, title = {Citizen Science: Development of a Low-Cost Magnetometer System for a Coordinated Space Weather Monitoring}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of ~3 nT at a 1 Hz sample rate. Crowd-sourced data from the PSWS systems will be collected into a central archive for the purpose of public access and analyzation along with space weather research. Ultimately, data from the PSWS network will combine the magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large scale current systems and ionospheric disturbances and events due to drivers from space and the atmosphere alike. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is entirely satisfactory for scientific investigations.

}, author = {Joseph Visone and Hyomin Kim and David Witten and Julius Madey and Nathaniel A. Frissell and John Gibbons and William D. Engelke and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @article {913, title = {Citizen science: Development of a low-cost magnetometer system for a coordinated space weather monitoring}, journal = {HardwareX}, volume = {20}, year = {2024}, month = {Jan-12-2024}, pages = {e00580}, abstract = {
As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of\ 3 nT at a 1 Hz sample rate. The measurement range of the sensor is\ \ nT) and is valid over a temperature range of -40 {\textdegree}C to +85 {\textdegree}C. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3{\textendash}30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is very adequate for scientific investigations.
}, keywords = {magnetometer}, issn = {24680672}, doi = {10.1016/j.ohx.2024.e00580}, url = {https://www.sciencedirect.com/science/article/pii/S2468067224000749}, author = {Kim, Hyomin and Witten, David and Madey, Julius and Frissell, Nathaniel and Gibbons, John and Engelke, William and Liddle, Anderson and Muscolino, Nicholas and Visone, Joseph and Cao, Zhaoshu} } @proceedings {828, title = {EclipseNB: A network of low-cost GNSS receivers to study ionospheric response to April 2024 solar eclipse}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

EclipseNB is an initiative of the Radio and Space Physics Lab (RSPL) at the University of New Brunswick (UNB) that enables high-impact scientific research and unique educational opportunities for High School students during the once-in-a-lifetime solar eclipse event over New Brunswick (NB) on April 8, 2024. This project will install state-of-the-art scientific infrastructure at a number of NB schools to monitor the dramatic and sudden modifications to the upper atmosphere associated with the eclipse. These high-value atmospheric measurements will provide rare insight into many open-ended scientific questions pertaining to eclipse-induced atmospheric modifications, while students throughout NB will have an exciting opportunity to participate in numerous EclipseNB activities such as infrastructure installation, data analysis, and scientific research. The infrastructure of EclipseNB is a provincial network of Global Navigation Satellite System (GNSS) receivers to monitor the electrically charged plasma of the upper atmosphere during the April 8, 2024 solar eclipse. A solar eclipse is a both a stunning celestial phenomenon and a rare opportunity to study numerous fundamental physical processes in the atmosphere and near-Earth space that are activated by a sudden and localized reduction in solar radiation. EclipseNB is ideally situated along the eclipse totality path to provide valuable measurements for ground-breaking scientific research, and to garner interest in young New Brunswickers in space physics, technology and engineering. EclipseNB installations are designed to be non-intrusive, with minimal impact on the sites involved. Installations include a self-contained enclosure that houses the GNSS receiver, a small single-board computer, and a cellular modem, as well as a receiving antenna mounted on a small pole with a clear view of the sky. The outdoor antenna is connected to the receiver with a low-loss RF cable. The sole requirement of hosting sites is electrical power, an indoor location to house the equipment enclosure, and an outdoor location to mount the antenna. Data collected by EclipseNB instruments will be stored on servers at UNB RSPL. The instrument will remain running after the solar eclipse in April 2024 and allow facilitating further research and education.

}, author = {Anton Kashcheyev and Chris Watson and P. T. Jayachandran} } @proceedings {830, title = {Operating GBO{\textquoteright}s 20m Radio Telescope with Ham Radio Students}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

As a part of the 40-week Exploring the Electromagnetic Spectrum - Ham Radio program with the National Radio Astronomy Observatory, students gain technical knowledge of the EMS and experience with hands-on applications through Amateur (Ham) Radio. One of the topics covered in this program is radio astronomy, and students had the opportunity to visit the affiliated Green Bank Observatory (GBO). Students learned how to operate the GBO 20-meter radio telescope in Green Bank, West Virginia using the Skynet Robotic Telescope Network. Students were trained to remotely operate the radio telescope, where they learned the parameters used for different types of observations and how to read the observational data acquired. In this presentation, we discuss the process by which students learned the parameters to operate the 20-meter telescope by observing and completing a comparative analysis of known pulsars.

}, author = {Mia Bridges and Alia Wofford and Erin McDonald and Xander Whittington-Speck and Danielle Rowland and Brenne Gregory and Daniel E. Reichart and Joshua B. Haislip and Vladimir V. Kouprianov and Steve White and Frank Ghigo} } @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 {868, title = {Ray-trace modelling of diurnal variation in two-hop sidescatter propagation}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Two-hop sidescatter, an off-great circle propagation mode enabling above-the-basic-MUF communications, is identified by low SNR and high spectral spread (width between -3 dB points). Observable at 7 MHz and above, as a daytime mode it enables propagation from 10s km to 100s km. Additionally, it may appear before, and or after, great-circle one-hop propagation as it operates with a lower F2 layer critical frequency. We have devised a computationally efficient modelling approach for two-hop sidescatter using 3D ray tracing. First, ray landing spots from a transmitter are found over 360{\textdegree}\ azimuth and a sensible range of elevations. Second, the process is repeated for a transmitter at the receiver. The key assumption is that reciprocity holds sufficiently to avoid the computationally demanding need to place a transmitter at every transmitter ray landing spot. A scattering metric, the product of the number of landing spots from transmitter and pseudo-transmitter in a 1{\textdegree}x1{\textdegree}\ area, is a useful approximation to the location and strength of the sidescatter. The off-great circle scattering location from the model has been verified by a rotating-antenna experiment at 14 MHz on paths from Northern California to Utah and Oregon using FST4W digital mode. The diurnal variations of sidescatter location and strength are particularly interesting for a meridional transmitter and receiver geometry: morning (local time) scatter from the east, from land on the California to Oregon path, with afternoon through nighttime scatter from the west, from the ocean. We discuss a qualitative comparison of hourly model simulations with signal level and circuit reliability data from FST4W spots. The nighttime minimum in both parameters is pronounced in the observations and model. An afternoon dip in circuit reliability, without reduction in signal level, is tentatively explained by the model showing strongest scatter alternating between east and west before settling to the west. We postulate that severe multipath scatter from both east and west, land and ocean, sufficiently increased frequency spread to reduce probability of decode for the ~6 Hz bandwidth FST4W mode. This study illustrates the usefulness of combining 3D ray tracing with purposeful observations to explain an underappreciated propagation mode.

}, author = {Gwyn Griffiths and Devin Diehl and R. Lynn Rhymes and Frederick Wahl} } @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 {762, title = {Development of HamSCI PSWS Ground Magnetometer and Data Visualization on the PSWS Central Website}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Hyomin Kim and Nathaniel A. Frissell and David Witten and Julius Madey and William D. Engelke and Tom Holmes and Majid Mokhtari and Scotty Cowling and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @proceedings {724, title = {Field-Aligned Potential Drops in an Ionospheric Streamer}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Field-aligned potential drops occur primarily in regions of strong upward field-aligned currents, where they can decouple the ionospheric and magnetospheric dynamics. They have been a challenge to incorporate into global magnetosphere modeling efforts. Low-entropy bubbles can form ionospheric streamers in the context of field-aligned potential drops. We have made a simple zeroth-order analytic model with order-of-magnitude reasonable field values. The model{\textquoteright}s parameter space comprises resistivity, bubble asymmetry, conductivity enhancement, and an additional parameter which can be used to adjust the entropy profiles across the bubble. We are currently exploring this parameter space and examining the resulting differences between the resulting ionospheric and magnetospheric electric fields (including electric field-reversals).\  An examination of whether bursty bulk flows or flow bursts are more likely to be responsible for streamers is ongoing.\  Both previous runs of the Rice Convection Model and data are being used to fit parameters and examine reasonable parameter regimes.

}, author = {Jason Derr and Sina Sadegzadeh and Richard Wolf and Frank Toffoletto and Jian Yang and Weiqin Sun} } @article {798, title = {Forging Amateur-Professional Bonds: An Overview of the HamSCI 2023 Workshop and the Upcoming Solar Eclipses}, volume = {79}, year = {2023}, month = {07/2023}, pages = {32-26}, type = {General Interest}, abstract = {

HamSCI {\textendash} the Ham Radio Science Citizen Investigation, a collaboration between the amateur radio and space science communities - held its sixth annual workshop this spring at The University of Scranton in Scranton, Pennsylvania.

}, issn = {0007-893X}, url = {https://cq-amateur-radio.com}, author = {Wilcox, R} } @proceedings {727, title = {Galactic Study of the Milky Way Galaxy Using Cold Hydrogen Data}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Radio waves offer a wide variety of opportunities for studying astronomical phenomena. This presentation is concerned with the study of cold Hydrogen H1 waves received from the Milky Way galaxy. The H1 lines are 21-cm radio waves that are produced as a result of the Hydrogen Spin flip phenomenon. The H1 data is received from the Society of Amateur Radio Astronomers (SARA) and processed to produce 6000 unique data points to conduct the galactic survey. The galactic survey consists of a heat map that shows the movement of the galaxy across the sky. The survey also consists of velocity plots which are produced in galactic coordinates to show the movement of the galactic arms across the galactic plane. The analysis of the velocity plots will allow an estimation of the galactic mass and further explore the discrepancy between observed mass and actual mass.\ 

}, author = {Muhammad Shaaf Sarwar and Mary Lou West and Richard Russel and Nathaniel A. Frissell} } @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 {716, title = {History of the Art of DXing and Contesting}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Rich in the history of amateur or ham radio is the art of DXing and contesting. DXing is short for distance. A DXpedition is a trip to operate in a rare location or country. Contests involve hundreds to thousands of operators attempting to {\textquotedblleft}work{\textquotedblright} or contact as many operators of a defined criteria as possible. These DXer{\textquoteright}s and contesters are generally very skilled. These skills involve {\textquotedblleft}pulling out{\textquotedblright} a single call sign out of a cacophony of dozens to hundreds of call signs, being able to hear and understand very weak signals, and being able to receive and transmit information rapidly and accurately. These operators have simple to large, advanced antenna systems, and equipment ranging from analog and tubes to state-of-the-art software defined radios (SDRs). They are a valuable resource to gathering data, as for example in the eclipse of 2017 and looking forward, to the eclipses of 2023 and 2024. How this all started is an important and fascinating part of ham radio history. This presentation will, in a humorous and personal way, present four important pioneers and tell their story, with their impact and influence. We will cover from the early 1900{\textquoteright}s to the early 1960{\textquoteright}s.

}, author = {Ron Wilcox} } @proceedings {717, title = {Involving the Lay Person in Citizen Science}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

How do we involve what is called the lay person in citizen science?\  The amateur radio community already has a head start due to the nature of their license and the activities that are part of amateur radio. This community encompasses a wide diversity of licensed operators. The education, backgrounds and careers are wide ranging. While surveys attempt to organize and quantify these individuals, both limited participation and a lack of personal interaction may limit their effectiveness. While not a scientific study, interacting with ham radio club members in a social, learning atmosphere including question and answer interactions, can give insights that will aid in involving them in citizen science. This presentation starts with my journey of giving presentations, to becoming involved in HamSCI and the eclipses. It will then look at what\  I have learned about these members and ham radio operators through these presentations and interactions. This is done through the perspective of a nonscientist, who is not formally of the scientific community, but is a member of HamSCI and involved with their activities.\ \ 

}, author = {Ron Wilcox} } @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 {743, title = {A Statistical Analysis of Heliobiology: Exploring Connections Between Space Weather and Human Health}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Solar storms are highly complex and powerful phenomena that have a significant impact on the Earth and the solar system at large. As scientists are learning more about the interaction of the sun and the Earth, some are turning their attention to the impacts that space weather might have on human health. This discipline of research on how the sun can directly affect biological organisms is called Heliobiology. The purpose of this study is to take a statistical approach to understand if there are any correlations between significant space weather events and human health. This will be accomplished by collecting data of solar activity from the solar cycle 23 minimum, and the maximum period of solar cycle 24, and comparing this data to cases of acute myocardial infarction (AMI) across regions of differing latitudes in the United States. Space weather data will be focused on periods of high KP and AE index, as well as the specific dates significant space weather events. The results of this study will be used to further investigate multiple variables and time frames to attempt to understand any correlations between space weather and human health that may exist.

}, author = {Anthony Williams and Tamitha Mulligan Skov} } @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 {603, title = {Consolidated Amateur Radio Reports as Indicators of Intense Sporadic-E Layers}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

A case study is presented to demonstrate the usefulness and validity of consolidated amateur ({\textquoteleft}ham{\textquoteright}) radio signal reports as indicators of the presence of ionospheric sporadic-E (Es). It is shown that amateur data can provide an important supplement to other techniques, allowing the detection of Es where no suitable ionosonde or satellite radio occultation measurements are available. The effectiveness of the approach is demonstrated by reference to ionosonde data, and the advantages and limitations of the technique are discussed.

}, author = {Chris Deacon and Cathryn Mitchell and Robert Watson} } @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 {650, title = {Magnetosphere-Ionosphere Coupling Studies Using the PSWS Magnetometer Network}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

As part of HamSCI Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer, which measures magnetic field strength and direction, has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of ~6 nT at a 1 Hz sample rate. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that its performance is very adequate for scientific investigations.

}, author = {Hyomin Kim and Sadaf Ansari and Julius Madey and David Witten and David Larsen and Scotty Cowling and Nathaniel Frissell and James Weygand} } @proceedings {601, title = {NASA/HPD/Space Weather/Citizen Science Programs Contributions to the HamSCI Workshop}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

This contribution to the HamSCI 2022 Workshop will provide: A\ summary of the goals of the NASA{\textquoteright}s Heliophysics Division (HPD); A summary of the strategies and activities of the space weather and citizen science programs in NASA{\textquoteright}s HPD.\ The presentation will discuss the relevance of the space weather and citizen science research programs to the HamSCI community.

NASA/HPD ROSES programs solicit research proposals so that amateur radio observations could be utilized for innovative science and technology research. NASA/HPD anticipates creating opportunities to enhance participation of the HamSCI community in observations of natural events in the 2023-2024 timeframe: The Heliophysics Big Year (HBY) including the upcoming annular solar eclipse (Oct 14, 2023) and total solar eclipse (Apr 8, 2024) over North America as well as the next solar max. NASA/HPD anticipates supporting HamSCI activities through space-based observations that can be leveraged by amateur radio scientists to enhance scientific contribution of the HamSCI community.
}, author = {E. Shume and J. Spann and J. Woodroffe and R. Friedel and J. Favors and W. Twetten and E. MacDonald and A. Rymer and S. Finn and J. Kozyra and K. Korreck} } @proceedings {647, title = {Opportunities for Research and Education with a Small Radio Telescope}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

A small radio telescope offers a wide range of opportunities for students and educators to explore the vast universe through radio waves. The incoming radio waves are slightly shifted due to the Doppler effect and the phenomenon is utilized to determine the speeds of target objects.\  This survey serves as a good introduction to Radio Astronomy and understanding the structure of the Milky Way. Using the knowledge and understanding of the galactic survey, further experiments can be conducted.

}, author = {M. Shaaf Sarwar and Nathaniel A. Frissell and Mary Lou West and Richard Russell} } @proceedings {644, title = {An Overview of Oblique Soundings from Chirp Ionosondes}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

An ionospheric sounder, typically known as an ionosonde, is a radar device which is used to make observations of the ionized layer of the Earth{\textquoteright}s upper atmosphere known as the ionosphere. The ionosonde works by transmitting high frequency (HF, 3-30 MHz) radio waves and observing the time delay of the ionospheric echoes. Ionosondes play an especially crucial role in our understanding both ionospheric dynamics and how radio wave propagation is impacted by the ionosphere. The data from an ionosonde is displayed in a type of plot known as an ionogram. A chirp ionosonde is a type of ionospheric sounder that produces ionograms by transmitting an HF signal that changes linearly in frequency with time. Conventional chirp ionosondes are used in a vertical sounding mode, in which signals are transmitted directly up to the ionosphere. This allows for measurements of electron density as a function of height for the bottomside ionosphere. Chirp ionosondes may also be used in an oblique sounding configuration, in which the transmitter and receiver are separated by a significant geographic distance. While the measurements of an oblique sounder are more complicated to interpret than a vertical sounder, a single transmitter can be used simultaneously by receivers in many different locations, thus allowing for a cost-effective increase in the number of ionospheric sampling points. The HamSCI Personal Space Weather Station plans to take advantage of this fact by using signals-of-opportunity from the global network of pre-existing chirp ionosonde transmitters. In this presentation, we give a brief overview of chirp ionosondes and their uses in studying ionospheric dynamics.

}, author = {Simal Sami and Nathaniel A. Frissell and Mary Lou West and Dev Raj Joshi and Juha Vierinen} } @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} } @proceedings {569, title = {Construction and operation of a HamSCI Grape version 1 Personal Space Weather Station: A citizen scientist{\textquoteright}s perspective}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=12718}, author = {Benedict, Robert and Waugh, David A.} } @conference {581, title = {Construction and Operation of a HamSCI Grape Version 1 Personal Space Weather Station: A Citizen Scientist{\textquoteright}s Perspective}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Measurement of Doppler shifts of high frequency (HF) radio signals emitted by precision frequency transmitters is a well-established technique for the detection of traveling ionospheric disturbances and other perturbations in the bottomside ionosphere. Because Doppler measurements require minimal instrumentation, this technique naturally lends itself to crowdsourced data collection, and purpose-built instrumentation platforms are desirable in order to maximize consistency and repeatability. However, even the best system only has value if it is used, and a robust and engaged community of citizen scientists is vital to sustaining instrumentation platforms. The Ham Radio Science Citizen Investigation (HamSCI) has developed a prototype, low-cost system for making HF Doppler shift measurements of signals from standards stations such as WWV (Fort Collins, Colorado, USA) and CHU (Ottawa, Ontario, Canada). This system, known as the Personal Space Weather Station Grape Version 1, consists of a low intermediate frequency (IF) mixer board, GPS disciplined oscillator, and Raspberry Pi. In collaboration with funded project scientists and engineers, volunteer HamSCI community members developed instructions for building and operating a Grape Version 1 on the HamSCI website. In this presentation, we explain the process for constructing a Grape Version 1 and discuss the experiences of volunteers who have built and are now operating this system. We also discuss preliminary data from these stations, which show dramatic Doppler shifts during sunrise and sunset and during solar events. Concurrent data from multiple proximal stations show shared features and can be used for validation. These stations constitute the first iteration of the Personal Space Weather Station network.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/845691}, author = {Hobart, Joseph R. and Farmer, James O. and Mikitin, Gary and Waugh, David and Benedict, Robert and Cerwin, Stephen A. and Collins, Kristina V, and Kazdan, David and Gibbons, John and Romanek, Veronica I. and Frissell, Nathaniel A.} } @conference {584, title = {An Easily Constructed High Resolution 3 Axis Magnetometer for Backyard Citizen Science}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, abstract = {

An answer to the need of the Hamsci Personal Space Weather Station Project for a low cost easily deployed 3 Axis magnetometer for earth surface geomagnetic field measurements based on the PNI RM3100 magneto-inductive magnetometer module for $31 in single quantities, compatible with Raspberry Pi class Single Board Computer data interfaces. Development of an inexpensive housing using off the shelf (OTF) components and a simple temperature stabilization technique and recommended interface will be discussed. Magnetometer system data will be compared with an appropriate Intermagnet site demonstrating the ability of this low cost instrument to achieve near 5nT resolution and noise, opening the potential for a diverse network of Citizen Scientist sites contributing data to better understand Earth{\textquoteright}s geomagnetic field.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/997017}, author = {Madey, Julius and Witten, David and Kim, Hyomin and Frissell, Nathaniel A.} } @proceedings {492, title = {"Geocaching" in the Ionosphere}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

"Geocaching"\ in the ionosphere {\textendash} The Search for MH370 by the amateur radio community Malaysian Flight MH370, a modern airliner B777, disappeared seven years ago on 2014.03.08 seemingly without a trace. Experts from various fields (i.e. Inmarsat) did not prevail til today. Maybe ham radio can contribute by using stored WSPR data from the database www.wsprnet.org. The data for that night{\textquoteright}s tragedy as well as the SAR operations exist in addition to many air accidents (AF447, MH17,...). The doomed flight happened close to the peak of solar cycle 24. In 2021 we have detected several aircraft in Antarctica such as a B787-9, two Dassault Falcon 900EX, an Iljuschin IL-76TD and a DC3C commuter airplane by conducting WSPR tests between DP0GVN as TX and ZL2005SWL as RX. Reference location data were used from Flightradar24. WSPR stations in Antartica were DP0GVN and the exploration ship Polarstern DP0POL/mm. QFA2904 flights to Anatarctica heading 180 degrees and retour were used to study backscatter effects from Perth (VK6) to Japan (JH3APN). Additional tests have been done in 2020 with repatriation flight QFA114 between JNB and PER over the Southern Indian Ocean (SIO). Other WSPR testing between ZS and KH6 and daily flights SIA478 and 479 have been conducted by monitoring WSPR data on www.wsprnet.org (secondary data) and www.kiwisdr.com (570 receivers worldwide with raw or primary data). Data have been gathered for the whole flight duration of app. 8 hours with signals from 7 MHz to 28 MHz and stations from Europe, Asia, North and South America as well as Australia and New Zealand. WSPR signals indicate the U-turn at 17:22 h UTC. Especially the "end game"\ offers a lot of data for Grayline, night and day reception, possible 28 MHz backscatter, short path (SP) as well as long path (LP) propagation. Trajectories have been studied by means of VOACAP etc. In depth cooperation between radio amateurs and science is encouraged with regard to interpretation of the received HF signals with emphasis on ionospheric behaviour and anomalies at mid-latitude (app. -30 degrees, -90 degrees) in the Southern hemisphere. WSPR data could eventually support the Inmarsat data and debris drift data by means of data fusion. They could also provide evidence if the wreckage is in the SIO or close to the Christmas Islands (VK9) as another theory based on research with hydrophones suggests.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=EA-94-A8-65-0F-B4-9E-48-AF-86-00-56-1C-28-35-64}, author = {Robert Westphal} } @conference {544, title = {HamSCI Personal Space Weather: Architecture and Applications to Radio Astronomy}, 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 = {

The Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project is a citizen science initiative to develop a new modular set of ground-based instrumentation for the purpose of studying the structure and dynamics of the terrestrial ionosphere, as well as the larger, coupled geospace system. PSWS system instrumentation includes radio receivers sensitive to frequencies ranging from the very low frequency (VLF) through very high frequency (VHF) bands, a Global Navigation Satellite System (GNSS) receiver to provide Total Electron Content (TEC) measurements and serve as a precision time and frequency reference, and a ground magnetometer sensitive to ionospheric and geospace currents. Although the PSWS is designed primarily for space weather and space science, its modular and open design in both hardware and software allows for a variety of use cases. The core radio instrument of the PSWS, the TangerineSDR, is a wideband, direct sampling 100~kHz to 60~MHz field programmable gate array (FPGA)-based software defined radio (SDR) receiver with direct applicability to radio astronomy. In this paper, we describe the PSWS and TangerineSDR architecture, show examples of how the TangerineSDR could be used to observe Jovian decametric emission, and discuss the applicability of the TangerineSDR to radio astronomy in general.

}, url = {https://rasdr.org/store/books/books/journals/proceedings-of-annual-conference}, author = {Nathaniel A. Frissell and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Typinski and William D. Engelke and David R. Larsen and David G. McGaw and Hyomin Kim and David M. Witten, II and Julius M. Madey and Kristina V. Collins and John C. Gibbons and David Kazdan and Aidan Montare and Dev Raj Joshi and Veronica I. Romanek and Cuong D. Nguyen and Stephen A. Cerwin and William Liles and Jonathan D. Rizzo and Ethan S. Miller and Juha Vierinen and Philip J. Erickson and Mary Lou West} } @conference {540, title = {HamSCI Personal Space Weather Station (PSWS): Architecture and Current Status}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, author = {Nathaniel A. Frissell and Dev Joshi and Veronica I. Romanek and Kristina V. Collins and Aidan Montare and David Kazdan and John Gibbons and William D. Engelke and Travis Atkison and Hyomin Kim and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Witten and Julius Madey and H. Ward Silver and William Liles and Steven Cerwin and Philip J. Erickson and Ethan S. Miller and Juha Vierinen} } @proceedings {561, title = {HamSCI Personal Space Weather Station (PSWS): Fall 2021 Update}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=1990}, author = {Frissell, Nathaniel A. and Joshi, Dev Raj and Collins, Kristina and Montare Aidan and Kazdan, David and Engelke, William D. and Atkison, Travis and Kim, Hyomin and Cowling, Scott H. and McDermott, Thomas C. and Ackermann, John and Witten, David and Madey, Jules and Silver, H. Ward and Liles, W. and Cerwin, Stephen A. and Erickson, Phillip J. and Miller, Ethan S, and Vierinen, Juha} } @proceedings {460, title = {Preliminary Data Analysis of PSWS Magnetometer Data}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

We report on the preliminary analysis of data obtained from newly developed magnetometers as part of HamSCI Personal Space Weather Station (PSWS) project. These systems are designed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ low-cost, commercial off-the-shelf, magneto-inductive sensor technology to record three-axis magnetic field variations with an adequate field resolution of ~10 nT at a 1 Hz sample rate. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability in unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at three locations across the US are presented and compared with the existing magnetometers nearby.\ 

}, author = {Hyomin Kim and Julius Madey and David M. Witten II and David Larsen and Scott H. Cowling and Nathaniel A. Frissell and James Weygand} } @proceedings {500, title = {PSWS Ground Magnetometer Hardware}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The path from candidate device for the magnetometer function of the PSWS to practical affordable working 24/7 data collection installations based on the low cost and readily available PNI RM3100 magneto-inductive sensor is discussed.\  Initial support board design using i2c bus connection to the host Odroid or Raspberry Pi class microprocessors with support for remote extension of the sensor to at least 100 feet with common CAT5 networking cable will be described as well as the accompanying test and logging software.\  Details of initial testing which revealed the need for temperature stabilization of the RM3100, verified remote operation to at least 500 feet, the subsequent design of an in-ground sensor housing made from common PVC water pipe and fittings and refinement of the microprocessor adapter board and remote board will be presented.

}, author = {Julius Madey and David Witten, II and Hyomin Kim and David Larsen and Scott H. Cowling and Nathaniel A. Frissell} } @proceedings {563, title = {PSWS Magnetometer Science Update}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=4555}, author = {Kim, Hyomin and Madey, Julius and Witten, David and Larsen, David R. and Cowling, Scott H. and Frissell, Nathaniel A. and Weygand, James} } @proceedings {567, title = {Software for Magnetometer Testing and Data Collection}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=10066}, author = {Witten, David} } @proceedings {468, title = {"Sprinkles" or "Mirrors"? Exploring the true nature of VHF propagation via sporadic-E}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Mid-latitude sporadic-E clouds (commonly abbreviated as {\textquoteleft}Es{\textquoteright}) are a transient feature consisting of thin layers of dense, but patchy, ionization which occur in the E region of the ionosphere. The process of formation is different from that of the rest of the ionosphere and it can produce much higher electron densities, sometimes permitting oblique reflection of radio waves up to 150 MHz.
The mechanism for the oblique reflection of VHF waves from Es layers has not been well described, with candidates including specular reflection, scattering, and magneto-ionic double refraction. The polarization and fading characteristics of waves reflected from Es layers are proposed as a marker for the presence or absence of magneto-ionic effects.\ 
An experimental system has been developed for rapid and accurate polarization and fading measurements at 50 MHz. The overall sensitivity of the system has been optimized by reducing environmental electromagnetic noise, giving the ability to observe weak, short-lived Es propagation events. The effect of the ground reflection on observed polarization has been analyzed and the induced amplitude and phase biases compensated for.
A measurement campaign in the summer of 2018 gathered a large quantity of data, using amateur 50 MHz beacons, at distances between 1,000 km and 1,650 km, as signal sources. The results provide compelling evidence that Es-layer propagation at 50 MHz exhibits the characteristics of magneto-ionic double refraction, but the thin, intense and variable nature of the reflecting region means that the reflected signals can have quite extreme characteristics. Some of the results are surprising, and are yet to be explained convincingly.
In this presentation, an overview of the experimental technique will be given, and the results described. Some of this information has already been published, but much of it is new.

}, author = {Chris Deacon and Ben Witvliet and Cathryn Mitchell and Simon Steendam} } @proceedings {462, title = {Toward interpretation of HF propagation data obtained by the HamSCI Community - Ray Tracers and Ionospheric Models}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Perhaps one of the most pressing questions the Ham Sci community needs to address is how data obtained by the tangerineSDR or other platforms will be interpreted to obtain scientifically useful information.\  One approach is to produce an appropriate forward model describing the ionosphere and use ray tracers to convert that model into observables that are measured using SDRs.\  The purpose of this talk is to discuss these issues in general terms, but also to discuss simulation strategies that could be useful for the data collected by a network of radio amateurs.\  I will also present on the development of an open source python-based 3-D Jones Stephenson Ray tracer and other developments out of my laboratory that are relevant to ray tracing, including implementation using cuda and the development of point-to-point ray tracing.

}, author = {Stephen R. Kaeppler and Scott Driggers and Andrew Wetzel and Alexander Murtha and Tedi Godfrey} } @conference {424, title = {HamSCI Distributed Array of Small Instruments Personal Space Weather Station (DASI-PSWS): Architecture and Current Status (Invited)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {N. A. Frissell and D. Joshi and K. Collins and A. Montare and D. Kazdan and J. Gibbons and S. Mandal and W. Engelke and T. Atkison and H. Kim and A. J. Gerrard and J. S. Vega and S. H. Cowling and T. C. McDermott and J. Ackermann and D. Witten and H. W. Silver and W. Liles and S. Cerwin and P. J. Erickson and E. S. Miller} } @conference {376, title = {Magnetometer Support for the Personal Space Weather Station and Related Projects}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The Personal Space Weather Station project requires the use of a high performance, yet affordable, ground based magnetometer component. Here we describe the design and testing of a magnetometer support module for that purpose. A sufficiently cost effective magnetometer offers the opportunity to capture new science by allowing construction of large and well populated grids of instruments. The module chosen makes use of sensor components based on magneto-inductive effects. Many types of magnetometer exist, all trading cost for performance across a huge range. Our goal was to design a sensitive instrument around commercially available components that would be versatile and low enough in cost to allow its deployment in novel ways.

}, author = {D. Witten III and F. Bonte and H. Kim} } @article {450, title = {Rapid and Accurate Measurement of Polarization and Fading of Weak VHF Signals Obliquely Reflected from Sporadic-E Layers}, journal = {IEEE Transactions on Antennas and Propagation}, year = {2020}, abstract = {

In the E-region of the ionosphere, at heights between 90 and 130 km, thin patches of enhanced ionization occur intermittently. The electron density in these sporadic-E (Es) clouds can sometimes be so high that radio waves with frequencies up to 150 MHz are obliquely reflected. While this phenomenon is well known, the reflection mechanism itself is not well understood. To investigate this question, an experimental system has been developed for accurate polarimetric and fading measurements of 50 MHz radio waves obliquely reflected by mid-latitude Es layers. The overall sensitivity of the system is optimized by reducing environmental electromagnetic noise, giving the ability to observe weak, short-lived 50 MHz Es propagation events. The effect of the ground reflection on observed polarization is analyzed and the induced amplitude and phase biases are compensated for. It is found that accurate measurements are only possible below the pseudo-Brewster angle. To demonstrate the effectiveness of the system, initial empirical results are presented which provide clear evidence of magneto-ionic double refraction.

}, keywords = {Brewster angle, ionosphere, radio noise, Radio wave propagation, VHF}, issn = {0018-926X}, url = {https://researchportal.bath.ac.uk/en/publications/rapid-and-accurate-measurement-of-polarization-and-fading-of-weak}, author = {Chris Deacon and Witvliet, Ben A. and Cathryn Mitchell and Simon Steendam} } @conference {389, title = {Temporal and Spatial Development of TEC Enhancements during Substorms}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Total electron count (TEC) enhancements due to space weather are a threat to communications and global positioning systems (GPS). It is known that TEC enhancements occur during magnetic storms and can cover large areas for many hours, but it is also not uncommon for TEC enhancements as large as 10 TEC units to occur during substorms. Although much is known about storm-associated TECs, the temporal and spatial characteristics of substorm-associated TECs are not well established. By combining two dimensional maps of TECs over North America and Greenland and with maps of ionospheric currents derived with the spherical elementary current method [Weygand et al., 2011], we investigate the temporal and spatial changes of TEC enhancement events for both a single substorm and for multiple substorms combined using a two dimensional superposed epoch analysis. Both the single event analysis and the statistical analysis show an increase of TECs during the expansion phase. Substorm values of the TEC enhancements peak within 10 min after auroral onset and recover to nominal levels after about 40 min. TEC enhancements occur mainly within the night side region 1 current system and cover millions of square kilometers. Furthermore, these enhancements appear to be associated with enhanced precipitating electron fluxes. These results address one of goals of the Space Weather Action Plan, which are to establish benchmarks for space weather events and improve modeling and prediction of their impacts on infrastructure.

}, author = {J. Weygand} } @conference {236, title = {Initial Results of HamSCI Ham Radio 21 August 2017 Eclipse Ionospheric Experiments}, booktitle = {American Meteorological Society Annual Meeting}, year = {2018}, month = {01/2018}, publisher = {American Meteorological Society}, organization = {American Meteorological Society}, address = {Austin, TX}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. Despite more than 60 years of research, questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. We present initial results from three amateur radio experiments designed to study the 2017 total solar eclipse: the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT). These experiments are coordinated by HamSCI, the Ham Radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://ams.confex.com/ams/98Annual/webprogram/Paper337094.html}, author = {N. A. Frissell and J. R. Ackermann and D. Bern and F. Ceglia and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. Gerzoff and P. Gladstone and S. W. Gunning and J. D. Huba and J. D. Katz and E. S. Miller and M. L. Moses and S. E. Reyer and S. W. Rose and A. Shovkoplyas and H. W. Silver and P. Smith and J. S. Vega and M. L. West and R. Williams} } @article {248, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, journal = {Geophysical Research Letters}, volume = {45}, year = {2018}, month = {05/2018}, type = {Research Letter}, abstract = {

On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium and high frequency radio propagation by the Solar Eclipse QSO Party (SEQP) citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at\ h >= 125 km altitude with elevation angles\ θ >= 22{\textdegree}, while 14 MHz signals refracted at\ h \< 125 km with elevation angles\ θ \< 10{\textdegree}.

}, issn = {1944-8007}, doi = {https://doi.org/10.1029/2018GL077324}, url = {https://doi.org/10.1029/2018GL077324}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and G. D. Earle and M. L. Moses and M. L. West and J. D. Huba and P. J. Erickson and E. S. Miller and R. B. Gerzoff and W. Liles and H. W. Silver} } @conference {277, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, booktitle = {Fall AGU}, year = {2018}, month = {12/2018}, publisher = {American Geophysical Union Meeting}, organization = {American Geophysical Union Meeting}, address = {Washington, DC}, abstract = {

On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium- and high-frequency radio propagation by the Solar Eclipse QSO Party citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h>=125 km altitude with elevation angles θ>=22{\textdegree}, while 14 MHz signals refracted at h \< 125 km with elevation angles θ \< 10{\textdegree}.

}, keywords = {Amateur Radio, Citizen Science, Ham Radio, HF propagation, ionosphere, solar eclipse}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/418915}, author = {Frissell, N. A. and Katz, J. D. and Gunning, S. W. and Vega, J. S. and Gerrard, A. J. and Earle, G. D. and Moses, M. L. and West, M. L. and Huba, J. D. and Erickson, P. J. and Miller, E. S. and Gerzoff, R. B. and Liles, W. and Silver, H. 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 {226, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {2017 Annual Meeting of the APS Mid-Atlantic Section}, year = {2017}, month = {11/2017}, publisher = {American Physical Society}, organization = {American Physical Society}, address = {Newark, NJ}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and M. L. West and G. D. Earle and M. L. Moses and H. W. Silver} } @conference {230, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {American Geophysical Union Fall Meeting}, year = {2017}, month = {12/2017}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and M. L. Moses and G. D. Earle and M. L. West and P. J. Erickson and E. S. Miller and R. Gerzoff and H. Ward Silver} } @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 {217, title = {Summary of Findings Associated with the 5 MHz Experiment}, booktitle = {HamSCI-UK}, year = {2017}, month = {10/2017}, publisher = {HamSCI-UK}, organization = {HamSCI-UK}, address = {Milton Keynes, UK}, author = {M. C. Walden} } @conference {214, title = {What{\textquoteright}s the difference? Amateur Radio and Radio Science}, booktitle = {HamSCI-UK}, year = {2017}, month = {10/2017}, publisher = {HamSCI-UK}, organization = {HamSCI-UK}, address = {Milton Keynes, UK}, author = {B. A. Witvliet} } @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} } @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.} }