@proceedings {1024, title = {Electromagnetic Vector Sensor Ionospheric Sounder (EMVSIS)}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {Ground-based ionosondes, also known as ionospheric sounders, are a bedrock sensor modality used by the space science community to monitor the bottom-side ionosphere. These HF radar systems have been used for decades to remotely measure the electron density and ion-drifts of this charged layer of the atmosphere. These systems have evolved as new technologies have come on the scene; one current example are electro-magnetic vector sensor antennas, which are compact arrays that measure the six components of an impinging electro-magnetic wave, allowing for estimation of direction of arrival and polarization. We will present a design that uses this new antenna technology, takes advantage of MIMO radar concepts and new waveform coding techniques. We call this system the Electro-Magnetic Vector Sensor Ionospheric Sounder (EMVSIS). The various design decisions and challenges will be discussed along with future improvements. We will preliminary results from various measurement campaigns and the types of validation and verification methods we are performing.}, author = {John Swoboda and Ryan Volz and Juha Vierinen and Frank Lind} } @proceedings {968, title = {Effect of near total solar eclipse on radio propagation of HF, weak-signal propagation reporter (WSPR) transmissions}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Background: A North American path of totality granted opportunity to investigate the effects of a solar eclipse on radio propagation. The weak signal propagation reporter (WSPR) modality is acclaimed for detecting low signal-to-noise transmissions and used to study radio propagation. {\textquotedblleft}Spots{\textquotedblright} are detected WSPR signals originating from a particular transmitter. Methods: The predicted maximum obscuration of the sun at the semi-rural New York field location (Maidenhead FN22, 42{\textdegree}N 74{\textdegree}W) was 97.6\%. The Zachtek WSPR Desktop Transmitter outputted 200mW WSPR transmissions cyclically on 80/40/30/20/17/15/12/10M amateur radio bands ({\textquotedblleft}bands{\textquotedblright}). The EFHW antenna system consisted of a horizontal ~66{\textquoteright} 16awg 20{\textquoteright} high wire in an east-west orientation, 49:1 toroidal impedance transformer, and 25{\textquoteright} RG58c/u coaxial cable. Before, during, and after the eclipse, WSPR transmissions cycled through 80M-10M (minus 60M) bands, transmitting for 105 seconds per band, or 14 minutes through all bands, followed by four minute of rest. Twelve multi-band transmission cycles were completed during the experiment; each complete transmission cycle was considered a {\textquotedblleft}time slot{\textquotedblright}. Propagated mileage for these spots was obtained from the WSPR Rocks! online repository. For each band, propagation mileage for spots in a given time slot were compared with those of all of the other time slots (Mann-Whitney U for non-parametric, independent data, one- and two- tailed, ρ \< 0.05) This was repeated for each band. When identified, significant findings suggest a particular band{\textquoteright}s aggregated propagation distances within a given time slot are different (longer or shorter) than those in that band{\textquoteright}s remaining time slots. Results: WSPR transmissions at 10.14MHz and 14.09MHz propagated significantly longer distances at the height of the eclipse and afterwards, compared to those preceding maximum sun coverage. This signal path lengthening was not observed in other bands. Solar eclipses may effect 30M and 20M radio wave propagation, causing transmission distances to lengthen at and following maximum solar obscuration.

}, author = {Mindy J. Hull} } @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 {973, title = {Electron thermionic emission and tunneling transport in spherically symmetric charged grains in dusty plasmas}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

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

}, author = {Rebecca Potter and Nina Tormann and Argyrios Varonides} } @proceedings {964, title = {Enhancing Lidar-GPS Fusion for Localization: Integrating Ionospheric Modeling with NeQuick G and V2V Implementation}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Lidar (Light Detection and Ranging) provides high-resolution mapping and odometry for localization but faces limitations when used alone. Conversely, GPS positioning is impaired by ionospheric irregularities{\textemdash}such as Total Electron Content (TEC) variations, scintillation, and gravity waves{\textemdash}which distort satellite signals and reduce accuracy. This work explores a multi-modal fusion approach that integrates Lidar and GPS to optimize localization by compensating for ionospheric-induced errors. In the first phase, we focus on enhancing the GPS component of the Lidar-GPS fusion using the Galileo-based NeQuick G model, a mathematical framework for simulating ionospheric variations. Utilizing NASA{\textquoteright}s Archive of Space Geodesy Data, we analyze the spatio-temporal distribution of Vertical TEC (VTEC). By applying Particle Swarm Optimization (PSO), we identify global VTEC maxima at different altitudes, shedding light on worst-case ionospheric disturbances. For example, our analysis predicts that on January 1, 2027, at 12:00 AM UTC, the highest VTEC values occur at coordinates (-9.8, -88) near Peru, a critical region where GPS accuracy may degrade. This phase aids in forecasting GPS performance fluctuations in high-disturbance zones and informs the optimization of Lidar-GPS fusion for precision applications, including autonomous vehicles and V2V communication. The second phase is an aspirational extension aimed at implementing a Vehicle-to-Vehicle (V2V) communication model using Lidar sensors. This planned work will address challenges such as third-vehicle occlusion and background visible light noise. By integrating Lidar landmark matching, SLAM, and 3D point cloud processing, we intend to enhance localization reliability in dynamic multi-vehicle environments. Ultimately, this study bridges atmospheric science and vehicular localization, demonstrating the synergy between Lidar-based SLAM, ionospheric modeling, and the potential for robust Lidar-driven V2V networking to improve autonomous navigation and road safety.

}, author = {Gamal Zayed and Ahmed Saeed and Yehea Ismail} } @proceedings {927, title = {EZIE-Mag: A low cost, science quality, magnetometer suite enabling global coverage}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

EZIE-Mag suite is an ultra-low cost, science quality measurements that enable the global observational coverage that is required to produce space weather nowcasting and forecasting. Industry have developed solutions that allow a low cost solution. We show the hardware solution, the OS, the post-processing solution, and the educational package.

}, author = {Jesper Gjerloev and R. Barnes and E. Adebayo and L. Kepko and T. Cline and N. Mosavi-Hoyer and J. Leibert and L. Regoli and M. Freil and D. Oztruk and A. Cohen and J. Fitzer} } @proceedings {827, title = {Early Results from the 2023 Eclipse Medium Wave Recordings}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

During the annular eclipse of 2023, HamSCI organized 13 volunteers in Canada, US, Mexico and Portugal to record the entire medium wave band (525-1705kHz) using software defined radios, both during the eclipse and for the same time period on other days, as well as during dawn and dusk periods. This medium wave data should extend our understanding of the eclipse{\textquoteright}s influence on the ionosphere by using frequencies well below HF. Since the eclipse, all 10 TB of medium wave data has been gathered and archived, followed by preliminary processing using inexpensive commercial software, such that all signal strength data from each participant is now available to 0.1Hz resolution for all broadcast channels.\  In addition, for all broadcast channels, and from every participant, useful visualization of signal variations during the eclipse is now available, as well as for all other time periods recorded.\ Many participants did see an effect of the eclipse on received signals.\  Comparisons of their rates of success compared with percentage of totality at their locations will be discussed. It{\textquoteright}s already possible to support some of the science aims of HamSCI with this gathered and archived data.\  Examples will be given of whether signal strength changes observed were symmetric compared with the onset and recovery timing of the eclipse. These changes will likely have been due to ionospheric response as the eclipse progressed. Visual examples will also be given of comparisons between the eclipse{\textquoteright}s effects on target signal characteristics to the effects caused by the passage of the daily dawn and dusk terminator.

}, author = {Nicholas Hall-Patch} } @proceedings {853, title = {Earth{\textquoteright}s Magnetic Field Migration and Its Effects on HF Propagation}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Propagation of radio waves in Earth{\textquoteright}s ionosphere and atmosphere critically depends on the strength and orientation of Earth{\textquoteright}s background magnetic field, due to the fact that electrons move much more readily along field lines than across them.\  The background magnetic field evolves continuously, driven by currents and other processes inside the planet{\textquoteright}s molten core.\  In particular, since 1990, the north magnetic pole has been migrating at an increased speed relative to its rate over most of the past century, and now moves more than 40 km/year.\  However, the south magnetic pole migration is considerably slower.\  The combination of these two effects has caused the global configuration of the geomagnetic field to change significantly.\  We will describe the sustained drift of magnetic field line locations over the last 40 years, with an emphasis on mid-latitudes where a large number of amateur radio operations take place.\  We will then provide estimates of induced changes in HF propagation over that time, using multiple models, and draw conclusions regarding the general climatology of propagation in various well used bands.

}, author = {Philip J. Erickson and William Liles} } @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 {874, title = {Effect of X-class Solar Flare on 40 Meter Propagation}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

WSPR data for North America is summarized to examine the impact of a reported x-class solar flare.\  The data is divided into distance categories to examine impact on different propagation methods, assuming that distance indicates propagation method. Very short distance (under 100 mile) for non-ionospheric, short distance (100 to 500 miles) for NVIS, medium distance (500-1500 miles) for E-layer propagation and longer distance (over 1500 miles) for F-layer.\  Signal to noise ratio is plotted by hour for the date of the flare. The impact of the flare is shown as a sudden decline in SNR for all distance ranges.\  While communications under 100 miles were initially presumed to involved non-ionospheric propagation, the flare impact at this distance indicates otherwise. WSPR data is also evaluated for its suitability in propagation analysis, noting strengths and weaknesses.

}, author = {Vincent LeVeque} } @proceedings {859, title = {Estimation of Ionospheric Layer Height by Measuring the Time Difference of Arrival (TDOA) Between 1 and 2 Hop Propagation Modes. 2023 Annular Eclipse Observations}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

A HamSCI science objective for the 2023 and 2024 eclipses is to use amateur radio stations to measure how the ionosphere changes with eclipse passage. Of particular interest is the change in effective ionization layer height caused by the momentary blockage of solar radiation. Layer height between two stations can be deduced from a Time of Flight (TOF) measurement but doing so requires complexity beyond the capability of most amateur radio stations. Particularly difficult requirements are precision absolute time references for both stations and calibration of the lengthy time delays incurred in modern DSP based transceivers. A simpler method that can be just as effective is to measure the Time Difference of Arrival (TDOA) between the 1- and 2- hop modes over paths and frequencies that support both modes. The 1-hop mode is shorter and arrives first, followed by the longer 2-hop mode. Geometric models based on virtual height or refractive ray tracing can be used to mathematically relate 1-2 hop TDOA to layer height. The measurement can be implemented by transmitting audio signals that are sensitive to a time delay when summed together, as happens in the receiver during simultaneous 1 and 2 hop propagation. Suitable audio waveforms include a 1-cycle audio burst, audio chirps of controlled sweep rate, and a pseudorandom noise burst. The TDOA measurement using the short pulses is performed by directly measuring the time difference between the two received pulses. The summation of a chirp waveform with a delayed copy of itself produces a beat note equal to the product of the sweep rate and the time delay that can be used to calculate TDOA. The TDOA can be extracted from both the PN bursts and chirps through an autocorrelation technique. The audio signals can simply be fed to the microphone input and recovered from the speaker output of ordinary SSB amateur radio equipment using audio .wav programs. This paper gives details of the method and of on-air experiments both before and during the 2023 Annular Eclipse.

}, author = {Steven A. Cerwin and Paul Bilberry and Sam Blackshear and Jesse T. McMahan and Kristina V. Collins and Nathaniel A. Frissell} } @proceedings {823, title = {Exploring Ionospheric Variability Through Doppler Residuals: A Study Utilizing the HamSCI Grape V1 Receiver}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

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

}, author = {Sabastian Fernandes and Gareth W. Perry and Tiago Trigo and Nathaniel A. Frissell and John Gibbons} } @proceedings {834, title = {Extreme Values in Short-Term 20 m Sequential Matched WSPR Observations}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Automated amateur radio networks, such as WSPRnet, daily compile data on hundreds of millions of radio contacts. This wealth of information is valuable for researchers exploring and forecasting High-Frequency (HF) propagation and its correlation with solar phenomena. A prerequisite for meaningful investigations is a comprehensive understanding and documentation of the inherent variability present in the data. Prior investigations highlighted the extreme short-term variability in SNR reports from 20-meter sequential matched observations, variability in excess of usual distributional assumptions.\  Here, we describe and model those extreme observations.\  Using descriptive statistics and logistic regressions, we provide evidence of some temporal and spatial patterns associated with the extreme SNR values and develop predictions for their occurrence.

}, author = {Robert B. Gerzoff and Nathaniel A. Frissell} } @proceedings {742, title = {Electrostatic and Quantum Size Effects in Short Channel MOSFETs}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {
Two dimensional electrostatics and quantum size effects have become important features of modern short channel MOSFET device design where the surface potential becomes spatially dependent affecting the threshold voltage Several nanometer channel lengths between Source and Drain cause quantum effects that need to be addressed in modern MOSFET design. We present a model of electron transport in the 2D inversion layer, where (a) electrostatic and (b) quantum size effects are pointed out.
}, author = {Robert Troy and Aidan Szabo and Argyros Varonides} } @proceedings {695, title = {Engaging the Amateur Radio Community with the Festivals of Eclipse Ionospheric Science}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

HamSCI{\textquoteright}s launching of the Solar Eclipse QSO Party in 2017 was, by any measure, a resounding success.\  Millions of data points were generated by amateur (ham) radio operators and they contributed greatly to research on ionospheric variability.\  \ The challenge before the HamSCI organization prior to the 2023 and 2024 solar eclipses appearing in North America:\  How to build on that success, engaging more participants, further assisting the geophysics community to answer the science questions to be raised by The Festivals of Eclipse Ionospheric Science (FoEIS)?\  The first step was reviewing what worked well in 2017, then building upon that success.\  Much like 2017, a QSO party, aptly named the Solar Eclipse QSO Party 2.0, was defined.\  For that event, amateurs will use their existing stations to contact one another in a friendly, competitive manner, using a mix of voice, Morse code and digital methods.\  Step two was the creation of a new event, the Gladstone Signal Spotting Challenge, which primarily makes use of digital communication techniques.\  It should attract those amateurs (and non-licensed short wave hobbyists) with a demonstrated interest in radio wave propagation.\  Having created an umbrella event, the FoEIS, plus two distinct competitions will allow HamSCI to promote the Festival to the general amateur radio community as before but also to more targeted audiences.\  Additional events will likely be added to the Festival, and they can be promoted to the ham community in a similar fashion.\  It is hoped the collective effort will lead to increased participation during the FoEIS as well as growth in the number of citizen scientists participating in HamSCI for the long term.

}, author = {Gary Mikitin} } @proceedings {690, title = {Evaluation of Global Ionospheric TEC Using Simultaneous Observations from Amateur Radio Networks, International Space Station, and NeQuickG Model for Space Weather Prediction}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Ionospheric electron density plays a significant role in long-distance communications and sky-wave propagation. Prediction of the accurate state of the ionosphere is necessary to understand the accurate signal perturbations thereby estimating the critical parameters for better signal transmission. The space weather impacts on such trans-ionospheric technological systems are evident. In this work, a web application is developed to represent the global day-to-day electron density variations from the NeQuickG model. Also, the ground-based HAM radio broadcast network hop data with different wavelengths (eg. 10 m and 20 m) and simultaneous top-side electron density with space-based International Space Station (ISS) probe data from floating point measurement units are examined. The electron density variations for the year 2017 are clearly represented. Optimization techniques are necessary to frame a denser spatial grid-based ionospheric electron density map from all the observations. It is essential to estimate the optimal weight function that can distribute the observation influence over empty grid bins with minimum error variance through a probabilistic approach. User-understandable metrics development exclusively for Amateur radio operators and civil aviation sectors is focused. In the near future, the developed web-based application could serve as a better visualization platform for space weather forecasting.

This project, Fellowship of the Ionosphere,\ is a Global Finalist in the 2022 NASA Space Apps Challenge.\ NASA Space Apps 2022 had 31,400+ registered participants from 162 counties and territories, with\ over 3000 submissions from 5327 teams. Global Finalists are ranked as one of the top 35 projects from all submissions.

}, author = {Gamal Zayed and Marcin Lesniowski and Pasumarthi Babu Sree Harsha and Matthew Downs and Daniel Metcalfe and Sila Kardelen Karabulut} } @proceedings {719, title = {An Expanded System to Track Traveling Ionospheric Disturbances and Other Effects Using Doppler-shifts of AM Broadcast Stations}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Traveling Ionospheric Disturbances, propagating variations in the ionosphere, can be tracked by observing the Doppler-shifted carriers of clear-channel AM broadcast stations.\  A system of receivers using Software-Defined Radios frequency stabilized by GPS has been developed, deployed and collecting data in the northeast United States.\  The existing system of 6 receivers will be built out to as many as 15 to cover much of the eastern US.\  This expanded network promises to be able to detect and track these TIDs as well as terminator, Spread-F and eclipse effects.

}, author = {David McGaw and Jackson Gosler and Justin Lewis and James LaBelle} } @proceedings {632, title = {Evaluation of Links Between Terrestrial Weather and Sporadic-E (Invited Tutorial)}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {
Abstract:\ The recent development of an experimental probability index for Es has enabled a more focussed approach to investigating the value of weather data in the troposphere as a geographical marker for Es in the ionosphere. Some early verification studies of this work will be presented together with examples of alternative graphical visualisations of ionosonde data to provide insights into the development of an Es event. The presentation will conclude with a discussion of the issues of verifying regional scale Es with isolated fixed site ionosonde data and suggest an outline for the next steps in the search for improved locational predictability of Es using meteorological forecast data.
Bio:\ The invited amateur radio tutorial will be presented by\ Mr. Jim Bacon G3YLA\ and will focus on the influences of Terrestrial Weather on radio propagation and the ionosphere. Mr. Bacon is a well-known retired meteorologist from the United Kingdom and is the recent recipient of the\ Radio Society of Great Britain Les Barclay Memorial Award\ to recognize those who have made excellent contributions to propagation research and understanding. Mr. Bacon actively develops the\ PropQuest website, which provides real-time Sporadic E Probability Index (EPI) that incorporates the factors of tropospheric weather, atmospheric gravity waves, meteors, wind shears, and atmospheric semi-diurnal tides.
}, author = {James Bacon} } @conference {643, title = {Evaluation of Techniques to Better Separate and Utilize Astronomical Radio Telescope Signals from those Due to Disturbances in the Ionosphere}, booktitle = {HamSC}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, organization = {HamSCI}, address = {Huntsville, AL}, abstract = {

Ionospheric disturbances impact radio signals that travel through them.\  These ionospheric scintillations are observed across the electromagnetic spectrum using a variety of methods.\  Previous studies have demonstrated that signals from radio telescopes can be used to measure and track these disturbances.\  Furthermore, a recent study suggests the separation of signals may be enhanced by concurrent measurements of ionospheric disturbances by multiple techniques and at different frequencies.\  This study discusses how astronomical and ionospheric signals from radio telescopes have been separated, how that separation might be improved by combining radio-telescope data with data from an alternate measurement methods and how ionospheric signals might be used to characterize ionospheric variability over both long- and short-term time scales.

}, author = {Robert Spalletta} } @conference {557, title = {Early Results from the Ionospheric Sounding Mode Using Chirp Ionosondes of Opportunity for the HamSCI Personal Space Weather Station}, booktitle = {2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)}, year = {2021}, abstract = {

The objective of the Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project is to develop a distributed array of ground-based multi-instrument nodes capable of remote sensing the geospace system. This system is being designed with the intention of distribution to a large number of amateur radio and citizen science observers. This will create an unprecedented opportunity to probe the ionosphere at finer resolution in both time and space as all measurements will be collected into a central database for coordinated analysis. Individual nodes are being designed to service the needs of the professional space science researcher while being cost-accessible and of interest to amateur radio operators and citizen scientists. At the heart of the HamSCI PSWS will be a high performance 0.1{\textendash}60 MHz software defined radio (SDR) [1] with GNSS-based precision timestamping and frequency reference. This SDR is known as the TangerineSDR and is being developed by the Tucson Amateur Packet Radio (TAPR) amateur radio organization. The primary objective of PSWS system is to gather observations to understand the short term and small spatial scale ionospheric variabilities in the ionosphere-thermosphere system. These variabilities are important for understanding a variety of geophysical phenomena such as Traveling Ionospheric Disturbances (TIDs) [2], Ionospheric absorption events, geomagnetic storms and substorms. We present early results suggesting signature of Traveling Ionospheric Disturbances (TIDs) from an ionospheric sounding mode that we intend to implement on the PSWS system, currently implemented on an Ettus N200 Universal Software Radio Peripheral (USRP) using the open source GNU Chirpsounder data collection and analysis code.

}, doi = {10.23919/URSIGASS51995.2021.9560441}, author = {Joshi, Dev and Frissell, Nathaniel and Liles, William and Vierinen, Juha and Miller, Ethan S.} } @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 {564, title = {An Easily Constructed High Resolution 3 Axis Magnetometer for Backyard Citizen Science}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=5631}, author = {Madey, Julius} } @proceedings {479, title = {e-POP RRI observations of the April 24, 2020 ARRL Frequency Measuring Test}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

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

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=34-2B-1B-32-C8-FC-4A-0B-5B-51-B9-1D-10-4E-F2-7F}, author = {Brian O{\textquoteright}Donnell and Gareth Perry} } @proceedings {459, title = {Estimation of Ionospheric Layer Height Changes From Doppler Frequency and Time of Flight Measurements on HF Skywave Signals}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The HamSCI community has been studying apparent frequency shifts in the reception of HF skywave signals from radio station WWV in Ft. Collins, CO. WWV is a standard time and frequency station with atomic clock accuracy. If the receiving station uses a GPS Disciplined Oscillator (GPSDO) for a frequency reference, the atomic clock accuracy on both ends guarantees any observed frequency shifts are attributable only to propagation effects through the ionosphere. Causes for frequency shifts in the received signal are recognized as complex and varied. A leading candidate is Doppler shift resulting from dynamic changes in refraction layer height. These, in turn, are caused by the diurnal transitions between night and day, passage of an eclipse shadow, and ionospheric disturbances originating from solar flares or X-ray events. For the case of changing refraction layer height, an analysis of Doppler frequency and Time of Flight (TOF) data can estimate the changes in skywave path length between the transmitter and receiver.\  This data can be used in conjunction with an assumed geometric model and propagation mode to infer the corresponding height profile over time. This paper postulates one possible mechanism for observed frequency swings and presents supporting experimental evidence. Comparisons between the calculated\  height profile derived from Doppler data and data from ray trace programs and ionosonde measurements are given.

}, author = {Steven Cerwin and Kristina V. Collins and Dev Joshi and Nathaniel A. Frissell} } @conference {583, title = {Experimental and Computational Methods to Analyze Complex Doppler Behavior of Ionospherically Induced Doppler Shifts on HF Signals}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

The HamSCI community has been studying apparent frequency shifts in the reception of HF skywave signals from radio station WWV in Ft. Collins, CO. Causes for frequency shifts in the received signal are recognized as complex and varied. Leading candidates are Doppler shifts resulting from dynamic changes in refraction layer height and the behavior of modes at incidence angles at the cusp between escape into space and refraction back to earth. Observations have shown the most radical frequency disturbances occur during the diurnal transitions between night and day, with the morning transitions exhibiting more radical behavior than evening. Other changes in solar radiation such as passage of an eclipse shadow or solar flares produce similar results. In all cases the frequency swings were found to follow the rate of change of propagation path length. Specific behaviors studied include mode splitting, where the Doppler shift diverges into multiple overtone-related tracks, modes that abruptly manifest and disappear during the transition, and asymptotic behavior where Doppler tracks exhibit a rapid frequency change followed by extinction. A morning transition spectrogram showing some of these characteristics is shown in the accompanying figure. This paper describes experiments and analytical procedures devised to better understand these phenomena. They include Time-of-Flight measurements reconciled with a geometric model of the ionosphere to infer propagation modes, use of the geometric model to calculate layer height changes from measured Doppler shifts, and comparison of specific features between spectrogram and ionosonde data sets. Data from two morning transitions and the 2017 total eclipse are given. Plausible explanations for several aspects of observed frequency swings are postulated.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/849071}, author = {Cerwin, Stephen A. and Collins, Kristina V. and Joshi, Dev Raj and Frissell, Nathaniel A.} } @proceedings {572, title = {Experimental and Computational Methods to Analyze Complex Doppler Behavior of Ionospherically Induced Doppler Shifts on HF Signals (Proceedings)}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=18161}, author = {Cerwin, Stephen A. and Collins, Kristina V. and Joshi, Dev Raj and Frissell, Nathaniel A.} } @proceedings {433, title = {Early Results of Festival of Frequency Measurement Experiment and June 21, 2020 Asian Eclipse}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Colllins, Kristina V.} } @conference {384, title = {EclipseMob: Initial Planning for 2024}, booktitle = {HamSCI Workshop}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

During the lead up to the 2017 Solar Eclipse and its aftermath, the EclipseMob team learned many things about crowdsourcing technology development and data collection. We are taking those lessons along with lessons learned from other crowdsourced citizen science programs to improve the EclipseMob experience for the upcoming 2024 Solar Eclipse. One such lesson is to start planning, building, and recruiting much earlier, and we are. EclipseMob is on schedule to finalize the design and testing of a new receiver system this summer. The 2017 Solar Eclipse collection platform relied on participants{\textquoteright} personal smartphones, which supplied the analog to digital converter (ADC), local oscillator, time, location, web access, and computational power. Our platform for 2024 eliminates the need for a smartphone by using a Raspberry Pi (RPi), analog amplifier, ADC, and GPS, in a self-contained unit. By eliminating the smartphone, the new design standardizes the hardware and increases economic accessibility. The 2024 platform is designed to collect WWVB signals at 60 kHz, as was the 2017 platform, but will also collect signals at lower frequencies such as the US Navy VLF transmitters. Those lower frequencies had to be ignored during the 2017 effort due to the limited bandwidth of the ADC in the smart phones. The construction process for the 2024 receiver kit has been heavily simplified, which we expect will result in increased participant success and satisfaction. In addition to modifying the data collection platform, 2024 EclipseMob is also changing its outreach approach. Instead of the centrally recruiting, training, and supporting participants, EclipseMob is switching to a train the trainer model. The EclipseMob team will work with and train a small subset of community leaders (from schools, libraries, ham radio clubs, etc.) to recruit and support participants locally. This should also increase the geospatial distribution of participants. In 2017 most participants were located in areas near the two main schools involved, which resulted in dense sampling in the Boston, MA and Fairfax, VA area. EclipseMob training materials will continue to meet the standards necessary for teacher continuing education credits and student learning.

}, author = {K. C. Kerby-Patel and L. Lukes and J. Nelson and W. Liles} } @conference {403, title = {Electromechanical ELF Transmitters for Wireless Communications in Conductive Environments (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Since the skin depth in ground or seawater is on the order of meters in the extremely low frequency (ELF) band, RF penetration through solids (e.g., into caves) and through water (e.g., to submarines) becomes feasible. This permits emergency communication for search and rescue missions and communication to submarines deep underwater. However, conventional antennas in this band are either impossibly large or highly inefficient (and thus power-hungry). For example, the U.S. military has in the past used ELF communication to communicate with submarines via Project Sanguine, a set of 76 Hz and 45 Hz transmitters with antennas stretching 14 miles and consuming a combined 2.6 MW during transmission. The FCC only regulates frequency bands between 9 kHz and 275 GHz, in part because electrical antennas are so inefficient below this range. This leaves a conveniently unregulated frequency range below 9 kHz (in the ELF and VLF bands) for unrestricted use. Proposed applications include studies of RF penetration through the ground for the study of the earth{\textquoteright}s crust and the study of the ionosphere. Moreover, unlike regulated ham radio bands, this unregulated frequency space has no restrictions on the use of encryption. Thus, communications systems below 9 kHz could be encrypted by any means desired, making this a highly lucrative application for private communications systems. We have developed a mechanically-based ELF antenna which replaces a conventional electrical antenna with a rotating permanent magnet. This radically different approach to wireless transmitter design allows us to take full advantage of the unique properties of the ELF band. Our design utilizes the high remanent flux density in rare earth magnet materials (e.g., NdFeB) to make ELF transmitters more power-efficient and portable. The current prototype operates at 90-110 Hz and supports data rates up to a few bits/sec; the next design iteration will operate at 300-700 Hz, allowing higher transmit data rates. In this presentation we describe the theory behind mechanically-based transmitters, describe the design of a practical transmitter, and show preliminary experimental results.

}, author = {Jarred Glickstein and Soumyajit Mandal} } @proceedings {437, title = {Evaluation of uBlox GPS Receivers Performance}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Ackermann, John} } @conference {413, title = {Emerging Trend in 5G, IoT and SDR}, booktitle = {IEEE North Jersey MTT/AP \& ED/CAS Chapters Seminar}, year = {2019}, month = {12/2019}, publisher = {IEEE North Jersey MTT/AP \& ED/CAS Chapters}, organization = {IEEE North Jersey MTT/AP \& ED/CAS Chapters}, address = {Newark, NJ}, abstract = {

2019_sdr_rohde_njit_041219.pdf

}, author = {Ulrich L. Rohde} } @conference {235, title = {Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation}, booktitle = {American Geophysical Union Fall Meeting}, year = {2017}, month = {12/2017}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center{\textquoteright}s partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. The Amateur Radio community has developed several automated receiving and reporting networks that draw from widely-distributed, automated and manual radio stations to build a near-real time, global picture of changing radio propagation conditions. We used these networks and employed HF radio propagation modeling in our investigation. A Ham Radio Science Citizen Investigation (HamSCI) collaboration with the American Radio Relay League (ARRL) ensured that many thousands of amateur radio operators would be {\textquotedblleft}on the air{\textquotedblright} communicating on eclipse day, promising an extremely large quantity of data would be collected. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon{\textquoteright}s shadow marched across the United States. Our expectations were the D-Region ionosphere would be most impacted by the eclipse, enabling over-the-horizon radio propagation on lower HF frequencies (3.5 and 7 MHz) that are typically closed during the middle of the day. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

}, author = {C. D. Fry and L. Rawlins and L. H. Krause and R. M. Suggs and J. K. McTernan and M. L. Adams and D. L. Gallagher and S. Anderson and R. Allsbrooks IV} } @conference {51, title = {e-POP Radio Science Using Amateur Radio Transmissions}, booktitle = {Fall AGU - Poster Presentation}, year = {2015}, month = {12/2015}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

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

}, author = {Nathaniel A. Frissell and Gareth Perry and Ethan S. Miller and Alex Shovkoplyas and Magdalina Moses and H. James and Andrew Yau} } @conference {52, title = {Experiment Design to Assess Ionospheric Perturbations During the 2017 Total Solar Eclipse}, booktitle = {Fall AGU - Poster Presentation}, year = {2015}, month = {12/2015}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

On August 21, 2017, there will be a total solar eclipse over the United States traveling from Oregon to South Carolina. Solar eclipses offer a way to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the east-west motion of the eclipse terminator, the speed of the transition, and the continued visibility of the corona throughout the eclipse interval. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses. These include changes in the ionospheric electric fields, changes in the Total Electron Content (TEC) along paths through the eclipsed region, and variations in the density and altitude of the F2 peak. Several studies over the past century investigated these effects; however, some of the results from these studies are contradictory. These contradictions and the studies{\textquoteright} limited spatial resolution leave many fundamental questions unanswered. The advent of several mid-latitude Global Positioning System (GPS) and radar networks in the past few decades, such as the Continuously Operating Reference Station (CORS) system and the Super Dual Auroral Radar Network (SuperDARN) radar system, have enabled ionospheric observations with hitherto unprecedented spatial resolution. Also, the establishment of several nationwide amateur radio reporting systems, such as the Reverse Beacon Network (RBN) that monitors radio wave propagation on the high frequency (HF) bands, offers the potential for evaluating changes in ionospheric conditions with unprecedented spatial resolution. We propose to study the effects of the total solar eclipse on the ionosphere using a combination of GPS receivers, the SuperDARN radar system, HF band amateur radio, and plasma modeling. The overall objectives of this study are to characterize the changes in F-region plasma morphology during the eclipse over a larger spatial domain than any previous eclipse experiment. In addition, the amateur radio component of our study offers a unique opportunity to further engage the amateur radio community nationwide in a scientific study.

}, author = {Magdalina Moses and Gregory Earle and Nathaniel Frissell and Stephen Kaeppler} }