@proceedings {817, title = {Grape 2 - The Finalized Version}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

A review of the architecture and operation of the final version of the Grape 2 Receiver.

}, author = {John Gibbons} } @proceedings {866, title = {The Grape III: Pondering new varietals for the RF vineyard}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Grape I is a straightforward low-IF receiver based on the venerable NE612 Gilbert cell chip. Grape II is a much more involved 3-frequency, computer-controlled receiver. Grape III will be--what?\  The CWRU Grape team will discuss possibilities for the next generation of inexpensive, high-accuracy receivers that will provide HamSCI, NIST, Canadian Research Council, and others a continuous data stream.\  Anticipation of signal processing, ease of manufacture, and ease of deployment will be among the top issues.\  Several receiver architectures and data collection modalities will be considered along with candidate signal analysis approaches and related chipsets.\  Notes will be taken from audience questions and suggestions, and new design teams will be solicited for the project.

}, author = {David Kazdan and John Gibbons} } @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} } @proceedings {689, title = {Grape Version 2 Hardware Description and Build Status}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A description of the Grape Version 2 high frequency (HF) Doppler receiver hardware and build status.

}, author = {John Gibbons} } @proceedings {652, title = {Geomagnetic Indices and The Ring Current}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Since the Space Age, the study of the near Earth space environment has become of great importance due to the advent of electrical systems, radio communications, and satellites which are directly affected by the state of the space environment around the Earth.\  The study of the {\textquoteleft}weather{\textquoteright} of this space environment comes in many shapes and forms but has mostly centered around the analysis and prediction of disturbances in the environment. These disturbances have been dubbed {\textquoteleft}geomagnetic storms{\textquoteright}, and their effects can range from inconsequential\  to, in the most severe cases, society altering.\  Several features of this space environment create changes at the ground level as they vary which can be measured and assigned values.\  In this poster we focus on three such values: Kp, F10.7, and Sym-H/Dst.\  The Sym-H/Dst index is of particular interest as it relates to one of the more prominent subsystems of the Earth{\textquoteright}s geospace environment, namely the ring current.

}, author = {Matthew Cooper and Andrew Gerrard} } @proceedings {486, title = {Gallifray: A VLBI Geometric Modelling and Parameter Estimation Framework for Black hole images using Bayesian Techniques}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Recent observations from the EHT of the centre of the M87 galaxy has opened up a whole new era for testing general relativity using BH (Black hole) images generated from VLBI. While different theories have their version of BH solutions, there are some {\textquoteleft}geometric models{\textquoteright} as well which can be approximated to visualise the image of a BH in addition to understand the geometric properties of the radio source such that ring size, width, etc. To incorporate and implement such framework, different methods and techniques are needed to be explored for doing such model comparison. We present {\textquoteleft}Gallifray{\textquoteright} [1], an open-source Python based framework for geometric modelling and estimation/extraction of parameters. We employ Bayesian techniques for the analysis and extraction of parameters. In my presentation, I will talk about the workflow, preliminary results obtained and applications of the library for image/model comparison. I will also talk about the scope of the library in testing Black hole images for any possible deviation from Kerr spacetime.
References:
[1] https://github.com/Relativist1/Gallifray/

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=10-AF-51-02-D7-02-36-CE-C0-BE-73-67-83-DB-7E-DE}, author = {Saurabh and Sourabh Nampalliwar} } @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} } @article {428, title = {The Great Collegiate Shortwave Listening Contest}, year = {2020}, author = {Frissell, N. A. and Liles, W. and Collins, K. and Kazdan, D} } @conference {324, title = {GPS Time Synchronization and Radio Detection for Ultra High Energy Cosmic Rays}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

In this talk, we will review GPS timing schemes and receiver selection for the synchronization of timing over the large distances of the Pierre Auger Observatory. An Experiment looking at spatial correlations of GPS timing errors will be discussed and then we{\textquoteright}ll move on to a brief introduction to radio methods for the detection of Extensive Air Showers.

}, author = {Rob Halliday} } @conference {317, title = {GPS-disciplined MEMS oscillators for amateur radio applications (Poster)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Islam - HamSCI 2019 Abstract.pdf

The frequency stability of reference oscillators (ROs) is a key performance limiter for all applications that require a timing or frequency reference, including precision sensing, inertial navigation systems, and reconfigurable radio transceivers for amateur radio. ROs based on ultra-high-Q micro-electromechanical systems (MEMS) resonators are promising replacements for conventional designs based on quartz crystals due to their compactness, amenability to monolithic integration with CMOS fabrication processes, low cost, and low power consumption. In this presentation, we will demonstrate i) a custom-designed single-chip CMOS sustaining amplifier, and ii) a highly-stable RO based on combining the amplifier with a vacuum-encapsulated breath-mode single-crystal silicon resonator (Q ≈ 105).

The free-running RO has a short-term Allan deviation $\sigma_{A}(\tau)$\ ≈ 1{\texttimes}10-8 at relatively small oscillation amplitudes (Posc ≈ -5 dBm). Further improvements in stability are obtained by increasing the oscillation amplitude such that the resonator becomes significantly nonlinear. In particular, Posc is adjusted in order to operate the resonator near one of its bifurcation points defined by electrostatic spring softening. The conversion of amplitude modulation to phase modulation (AM-to-PM) is greatly reduced near such points, thus reducing phase noise to levels that cannot be obtained using linear resonators. Thus, operation of MEMS resonators beyond the threshold of nonlinearity is promising for improving short- and medium-term RO stability. Moreover, the proposed RO can also be locked to GPS for greatly-improved long-term stability, thus enabling its use as a miniaturized, low-cost, and rugged secondary frequency standard in amateur radio applications.

}, author = {Mohammad S. Islam and George Xereas and Vamsy P. Chodavarapu and Soumyajit Mandal} }