@proceedings {860, title = {Construction of a Table-Top Antenna Range for Learning Electromagnetics Concepts}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Antenna construction and measurement provide an effective method of teaching electromagnetic and antenna concepts, including polarization, gain, directivity, and reflection. During the Spring 2024 semester, the University of Scranton EE 448 Electromagnetics II class is undertaking a project to build a table-top antenna range at 2450 MHz (λ = 12 cm). The table top range will give hands-on visual and intuitive reinforcement of abstract concepts covered mathematically in the course textbook. This frequency was chosen due to the convenient size of antennas and the fact that the antennas will be usable in the 2.4 GHz Industrial, Scientific, and Medical (ISM) and amateur bands. ISM band applications include WiFi, Bluetooth, RFID, NFC, and more. In this presentation and poster, we demonstrate three types of antennas the class has built so far: dipoles, dipoles with corner reflectors, and loops over ground planes. We also demonstrate the use of a NanoVNA to measure antenna properties, as well as show ideas for future projects.

}, author = {Augustine Brapoh and Matthew Dittmar and Aidan Szabo and Robert Troy and Nathaniel Frissell and Stephen A. Cerwin} } @proceedings {712, title = {Time Difference of Arrival (TDOA) Measurements on Multipath Propagation Modes to Profile Ionospheric Layer Height Changes During Solar Eclipses}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A science objective for the 2023 and 2024 eclipses is to measure how HF propagation changes with eclipse passage. Two parameters of interest are the change in effective in F2 ionization layer height caused by the momentary blockage of solar radiation and the symmetry in recovery as solar radiation returns after eclipse passage. The changes in layer height that occurred during the 2017 eclipse and that occur daily at dawn and dusk have been studied by both Doppler analyses and, in the latter case more directly by Time-of-Flight (TOF) measurements. The WWV analyses were enabled by the station{\textquoteright}s precise carrier frequency accuracy and by transmission of timing markers precisely synchronized to UTC. The objective of the proposed SEQP experiment is to acquire similar data from amateur radio stations using common amateur radio equipment and authorized frequencies. But most amateur radios possess neither the frequency stability for accurate Doppler analysis nor an easy way to time-synchronize for accurate TOF measurements. However, over propagation paths that support transmission of multiple hops, an audio chirp waveform can be transmitted to measure the Time Difference of Arrival (TDOA) between multipath modes, particularly the 1- and 2- hop modes. For a given TX-RX path, the arrival times for multiple hops from a common ionization layer are geometrically locked together by ground distance, layer height, and geometry. Therefore a 1-hop, 2-hop TDOA measurement could be used to infer effective layer height and track how it changes with time over the course of the eclipse. The method is like a conventional chirp radar technique but instead of the usual swept carrier an audio chirp is fed into the microphone input of a radio transmitter operating in voice mode. The TDOA approach eliminates the need for precise frequency and timing accuracy, allowing the use of simple amateur radio equipment. This paper presents the methodology proposed for use in the experiments, gives examples of TDOA measurements already performed using the scientific waveforms being transmitted at 8 and 48 minutes after the hour by WWV and WWVH, and discusses anticipated issues associated with the method.

}, author = {Stephen A. Cerwin} } @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} } @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} } @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} }