@proceedings {932, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

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

}, author = {Alexandros Papadopoulos and Gerard Piccini and Nathaniel Frissell and Steve Cerwin and Jesse McMahan and Paul Bilberry and Blackshear Samuel and Aidan Montaigne and Kristina Collins and Robert Spalletta} } @proceedings {934, title = {The HamSCI Book Club}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

\ We will discuss several radio-related works of English literature: \ Romeo \& Juliet\ romeo-and-juliet_PDF_FolgerShakespeare.pdf\ and Code Poems\ Weiner_Hannah_Code_Poems.pdf

}, author = {David Kazdan and Kristina Collins and Leah Davydov} } @proceedings {928, title = {HamSCI in OpenSpace: Toward Unified Visualizations of Geospace Data}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

As HamSCI efforts developing the PSWS network continue, we amass stations and data that can help fill in the gaps in our understanding of the geospace system. However, the counterintuitive scales of the geospace system present visualization challenges, and demand flexible and intuitive tools that can showcase data and simulations over a range of spatial and temporal scales with appropriate fidelity. OpenSpace is open-source interactive data visualization software designed to visualize the entire known universe and portray our ongoing efforts to investigate the cosmos. Designed for use in planetarium domes, it can also be deployed on desktop computers, and is well-supported by a vibrant open-source development community of over twenty years. In this talk, I{\textquoteright}ll demonstrate how OpenSpace can be used as a visualization platform for HamSCI work and related data. I{\textquoteright}ll also discuss the potential for VR integration and spatialized sonification and audification in OpenSpace.

}, author = {Kristina Collins} } @proceedings {930, title = {The Solar Eclipse Inverse Problem}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI Personal Space Weather Station (PSWS) is a distributed network that includes magnetometers and high frequency receivers. The Great Radio Amateur Propagation Experiment (GRAPE) is a collection of PSWS receivers that record Doppler shift from national time standard signals. The Grape project includes Grape 1 receivers recording Doppler and spectral data as well as the upgraded Grape 2 three channel receivers and the multi-channel WSPR (Weak Signal Propagation Reporter) Grapes. The network collected data during the 2023 and 2024 solar eclipses on frequencies ranging from 2.5 to 20 MHz. The recorded Doppler shift indicates a change in signal path caused when the signal passes through the ionospheric layers in the Earth{\textquoteright}s atmosphere. Due to the scale and variability of the ionosphere, these measurements are sparse and are not accompanied by a known forward model. The reconstruction of eclipse period ionospheric behavior can therefore be viewed as a mathematical inverse problem. We explore various mathematical techniques and algorithms that could be used to solve the inverse problem and model the real time ionospheric behavior.

}, author = {Rachel Boedicker and Nathaniel Frissell and John Gibbons and Kristina Collins and David Kazdan} } @proceedings {858, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

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

}, author = {Alexandros Papadopoulos and Gerrard Piccini and Thomas Pisano and Nicholas Guerra and Matthew Felicia and Evan Hromisin and Aidan Montare and Kristina Collins and Paul Bilberry and Samuel Blackshear and Steve Cerwin and Nathaniel A. Frissell} } @proceedings {835, title = {Comparative Analysis of Medium Scale Travelling Ionospheric Disturbances: Grape PSWS vs. SuperDARN}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are periodic fluctuations in ionospheric electron density associated with atmospheric gravity waves. They are characterized by wavelengths of 50-500 kilometers and periods of 15-60 minutes. This study presents initial findings from a comparative analysis of MSTID observations sourced from two distinct systems: the Super Dual Auroral Radar Network (SuperDARN) and the Grape Personal Space Weather Station (PSWS). The Grape PSWS, developed by the Ham Radio Science Citizen Investigation (HamSCI), is a small ground-based remote sensing device aimed at monitoring space weather parameters, including MSTIDs. It achieves this by monitoring a 10 MHz transmission from WWV, a National Institute of Standards and Technology (NIST) time standard station located near Fort Collins, Colorado, USA. In contrast, SuperDARN comprises a global network of high-frequency radars that offer extensive coverage of ionospheric plasma motion. This comparative investigation focuses on aligning MSTID observations obtained from Grape PSWS data with SuperDARN radar data. By investigating datasets from both platforms, these findings serve as initial results for an ongoing investigation of MSTIDs, laying the groundwork for a comprehensive understanding of their dynamics and impacts on ionospheric variability and space weather.

}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Bharat Kunduri and J. Michael Ruohoniemi and Joseph Baker and William Liles and John Gibbons and Kristina Collins and David Kazdan and Rachel Boedicker} } @proceedings {824, title = {Initial Review of the October 2023 Grape Eclipse Data}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The Great Radio Amateur Propagation Experiment (GRAPE) is a network of Doppler receivers that function as a distributed multi-static radar. The Grape network received 10 MHz doppler data from the NIST time and frequency station WWV in Fort Collins, CO during the 2023 October annular eclipse. Grape receivers in the network recorded a spectrum of Doppler shift data of the signals after they passed through the eclipse modified ionosphere. An updated version of the receiver will\  be deployed to expand the network and collect similar data during the 2024 April total solar eclipse. We present initial data and results of the 2023 eclipse and discuss the upcoming eclipse.

}, author = {Rachel Boedicker and Nathaniel A. Frissell and John Gibbons and Kristina Collins} } @proceedings {691, title = {Climatology of Ionospheric Variability with MSTID Periods Observed Using Grape v1 HF Doppler Receivers}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Veronica Romanek and Nathaniel Frissell and Kristina Collins and John Gibbons and David Kazdan and William Liles} } @proceedings {694, title = {Measuring Daily Ionospheric Variability and the 2023 and 2024 Solar Eclipse Ionospheric Impacts Using HamSCI HF Doppler Shift Receivers}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

This project will study ionospheric variability across the continental United States (CONUS) generated by dawn/dusk transitions and two solar eclipses occurring in 2023 and 2024. Dawn and dusk produce a complex response in observed ionospheric variability that is still not completely understood. A network of Global Navigation Satellite System (GNSS) stabilized/synchronized high frequency (HF) receivers known as Grapes will be used for the study. Thirty Grape receivers will be deployed throughout North America to optimize the study of the ionospheric impacts simultaneously received from two locations. Additional stations will be funded by the HamSCI amateur radio community. This project will generate observations to answer the scientific questions: (1) How do dawn and dusk ionospheric variability vary with local time, season, latitude, longitude, frequency, distance, and direction from the transmitter? (2) Is eclipse ionospheric response symmetric with regard to the onset and recovery timing? (3) How similar is the eclipse to the daily dawn and dusk terminator passage? (4) Would multipath HF mode-splitting in the post-eclipse interval be similar to dawn events? (5) Would the response be different for two eclipses?

This project is part of the Ham Radio Science Citizen Investigation (HamSCI) program and will be open to volunteers who want to field instruments and contribute to scientific analysis and discussion. This project will also establish a new network of DASI instruments that, due to its low cost and operation by volunteers, has the potential to provide measurements for years to come. This project will support students (undergraduate, MS and Ph.D.).

}, author = {Rachel Boedicker and Nathaniel Frissell and Kristina Collins and John Gibbons and David Kazdan and Philip J. Erickson} } @proceedings {729, title = {The potential of HamSCI Doppler Observations for inferring Solar Flare Effects on the Ionosphere}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A solar flare is a space weather event that causes a transient in the ionospheric system at sub-auroral, middle, and lower latitudes, commonly known as the solar flare effect (SFE). Sudden enhancement in high-frequency (HF) absorption is a well-known impact of solar flare-driven Short-Wave Fadeout (SWF). Less understood, is a perturbation of the radio wave frequency as it traverses the lower ionosphere in the early stages of SWF, also known as the Doppler flash. SuperDARN radar network is typically used to study the Doppler flash. Previous investigations have suggested two possible sources that might contribute to the manifestation of Doppler flash: first, enhancements of plasma density in the D and lower E-regions; second, the lowering of the reflection point in the F-region. HamSCI is a platform that publicizes and promotes scientific research and understanding through amateur radio activities in the HF band. Studies have shown that solar flare-driven HF absorption can affect amateur radio signal strength. Recent development showed that the HamSCI Doppler observations can provide insight into the physics behind changes in phase path length of the trans ionospheric radio signals. In this study, we will demonstrate how HamSCI Doppler observations can be used to infer flare-driven changes in the ionospheric properties and associated Doppler flash. Furthermore, if successful the study will also quantify Doppler flash recorded in HamSCI as a function of flare strength, flare location on the solar disk, operating frequency, and location on the Earth. Upon successful quantification of Doppler flash, we will compare its properties with previous studies that used SuperDARN observations.

}, author = {Shibaji Chakraborty and Kristina Collins} } @proceedings {730, title = {Through a Channel Dispersively with FB Copy: An Experience of fldigi Operating Modes}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Bring a laptop with fldigi installed for the microphone/speaker soundcard
Have some small .jpg files to send.
Try different phase and frequency digital modes in noise, multipath, and dispersion, discuss the fldigi {\textquoteright}scope views.

}, author = {Kristina Collins and Rachel Boedicker and David Kazdan} } @proceedings {759, title = {An Update on the WWV/H Modulation Test and WWV ARC}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The WWV/H Scientific Modulation Test continues after 16 months broadcasting at minute 8 on WWV and minute 48 on WWVH.\  Initial evaluation of the recordings show promise in determining time-of-flight and other characteristics.\  Efforts have started to place a KiwiSDR receiver on Kauai for an evaluation of WWVH broadcasts similar to those made of WWV.\  The WWV ARC held the Tune In: The WWV Frequency Celebration at the beginning of March to mark the 100th anniversary of WWV providing standard frequencies.\  NIST and HamSCI presented talks on March 2,\  NIST provided tours of the Boulder and WWV facilities March 3, and The Fort Collins Museum of Discovery hosted the Tune In: The WWV Frequency Celebration open house on March 4.\  Various aspects of amateur radio were showcased including traditional HF (with a station), ARISS, ARES, satellite, HamSCI, and of course a history of WWV.

}, author = {Dave Swartz and Kristina Collins} } @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 {477, title = {December 2020 Eclipse Festival Analysis}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

A crowdsourced science experiment called the December 2020 Eclipse Festival of Frequency Measurement was carried out for the total solar eclipse across South America on December 14, 2020. Over 80 stations around the world recorded WAV files of 10 MHz time standard stations. We have undertaken to process and visualize this data, and identify geophysical features within it. This poster will summarize our work to date.\ 

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=24-20-1F-16-09-FF-74-70-E0-78-1D-88-6D-21-D5-3F}, author = {Kristina Collins and David Casente and Joanna Elia and Marius Mereckis and David Meshnick} } @conference {539, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

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

}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Clair Trop and Kristina Collins and Gareth Perry} } @proceedings {478, title = {A Survey of HF Doppler TID Signatures Observed Using a Grape in New Jersey}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=6A-B6-94-74-A1-46-CF-D2-AC-BA-F3-58-2E-71-17-97}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Kristina Collins and John Gibbons and David Kazdan} } @proceedings {494, title = {W3USR and The Great Collegiate Shortwave Listening Contest}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/Default.aspx?s=1B-12-5C-9B-5C-AF-F5-8B-AC-62-CD-DD-D5-51-6A-9A}, author = {M. Shaaf Sarwar and Veronica I. Romanek and Thomas Baran and Jonathan Rizzo and Steve Holguin and Jonathan Rizzo and Nathaniel A. Frissell and William Liles and Kristina Collins and David Kazdan} } @conference {360, title = {A Low-Cost Citizen Science HF Doppler Receiver for Measuring Ionospheric Variability}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Advancement in understanding short term and small spatial scale ionospheric variability requires global high time and spatial resolution measurements. Professional ionospheric sounding networks are extensive and capable, yet more measurements are still needed due to the strongly magnetized nature and large extent of the ionosphere. High Frequency (HF, 3-30 MHz) radio signals are refracted by the ionosphere, and therefore are modulated by processes such as traveling ionospheric disturbances (TIDs) and geomagnetic storms. By measuring the amplitude and Doppler shift of trans-ionospheric HF signals, it is possible to detect signatures of ionospheric absorption and changes in propagation path length. We present a design for a low-cost citizen science HF multi-band receiver that measures the amplitude and Doppler shift of reference signals of opportunity from the US National Institute of Standards and Technology station WWV and the Canadian Institute for National Measurement Standards station CHU. The receiver will make 1 s cadence measurements on nine HF beacon frequencies and subsequently upload the results to a central server for scientific analysis. The local user will be able to review data daily, both locally and in aggregate on a web server, and participate in discussion of the ionospheric measurements. This receiver forms one component of the low-cost version of the Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS), and is designed with the intention of distribution to hundreds to thousands of citizen science observers. Preliminary results from the prototype receiver will be presented.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/602677}, author = {Kristina Collins and David Kazdan and John Gibbons and Aidan Montare and Skylar Dannhoff and Philip J. Erickson and Nathaniel A. Frissell} }