SARA 2022 Eastern Conference Abstracts

 

SARA 2022 Eastern Conference Abstracts

 

 

 

Keynote

 

Amateur Radio Astronomy

 

Possibilities and Limitations
Do’s and Don’ts

 

Wolfgang Herrmann, Astropeiler Stockert e.V.

 

Amateur radio astronomy covers a wide field from meteors, our solar system, objects in the milky way and extragalactic sources. Very different physical processes cause the emission which can be observed. Due to great variety of observing objects, different approaches are required for each of these areas.

 

The talk will give an overview of the options which are open to amateurs and discuss the required instrumentation and tools to be successful. Examples will be given from various amateur observatories what can be achieved. Naturally, there are also various pitfalls which can get in the way. The talk will discuss, what mistakes should be avoided and what path might be good to become a “professional amateur”.

 

 

 

Polarized pulse pairs in the search for extraterrestrial intelligence

 

William J. (Skip) Crilly Jr

 

 

 

A system of radio telescopes has been operated since 2017 to search for hypothetical interstellar microwave communication signals. The candidate signal includes two narrow bandwidth pulses having differing polarization and near-zero interarrival time and frequency. Knowledge of random noise statistics permits the calculation of the likelihood of false positives during a scan of Right Ascension. Robust RFI excision has been implemented. The search has resulted in anomalous measurements that include geographically-spaced simultaneous pulse observations, and apparent anomalous symbol repetition and quantization, observed in a celestial direction near the star Rigel. This presentation summarizes the hypothetical communication system, describes salient experimental results, and proposes conclusions and further work.

 

 

 

Web Application for  LoFASM Data Mining

 

Tom Hagen

 

 

 

The Low Frequency All Sky Monitor (LoFASM) project monitors celestial and other radio emissions in the 5-88 MHz range.  A LoFASM station consists of an array of twelve crossed dipole antennas originally developed for the Long Wavelength Array system at the VLA observatory in Socorro, New Mexico.  There are currently four operational LoFASM stations scattered across the United States.

 

 

 

The LoFASM system was created in 2015 by the University of Texas-Rio Grande Valley (UTRGV).  Louis Dartez, at the time a graduate student at UTRGV, developed the system to operate the array and archive the data.  Dr. Dartez has been helping me create a web-based application to enable human inspection of the hundreds of plots created each day by just one station.  The goal is to identify transient signals and other anomalies.  It is hoped that after enough plots have been inspected, patterns will emerge so that an artificial intelligence system can be created to perform the same task.

 

 

 

The web app is based on the open-source Dash Plotly data analytical software.  This gives the developer Python tools and libraries to analyze the raw LoFASM data.  An interactive web graphical display is created for the user to mark and record anomalies.  In addition, the setup runs on a virtual Docker container.  The Docker system allows me to develop the interface on a Raspberry Pi 4 with the intent of eventually moving the intact container over to an online web service so that many people can use it to go through the data and record their observations.  

 

 

 

Introduction to Radio Astronomy

 

Ed Harfmann

 

 

 

Join us for an introduction and review of radio astronomy.  We will cover:

 

·         Why radio astronomy is important to our understanding of the universe.

 

·         A brief review of how it got started to when it became seriously recognized as a serious science.

 

·         What do the professionals use and why it is important to amateurs.

 

·         An overview of what people do to get started.

 

·         “Speed bumps” that you can expect and should not detract from your getting started.

 

 

 

This introduction is not meant to explain everything but rather to allow you to see and understand enough to get started in your own adventure as an amateur radio astronomer.

 

 

 

The Radio JOVE Project 2.0

 

Dr. Chuck Higgins, et.al.

 

 

 

C. Higgins (1), S. Fung (2), L. Garcia (3), J. Thieman (4), J. Sky (5), D. Typinski (6), R. Flagg (7), J. Brown (8), F. Reyes (9), J. Gass (10), L. Dodd (11), T. Ashcraft (12), W. Greenman (13), J. Cox (14), and S. Blair (15)

 

 

 

(1) Middle Tennessee State University, Murfreesboro, TN 37132

 

(2) ITMPL/NASA GSFC, Greenbelt MD 20771

 

(3) SGT/NASA GSFC, Greenbelt MD 20771

 

(4) UMBC/NASA GSFC, Greenbelt MD 20771

 

(5) Radio Sky Publishing, Louisville, KY, 40214

 

(6) AJ4CO Observatory, High Spring, FL 32655

 

(7) RF Associates, Honolulu, HI 96826,

 

(8) Hawks Nest Radio Astronomy Observatory, Industry, PA 15052

 

(9) Dept. of Physics & Astronomy, University of Florida, Gainesville, FL 32611

 

(10) CNSP/NASA GSFC, Greenbelt, MD 20771

 

(11) Georgia Amateur Radio Astronomy Observatory, Jasper, GA 30143

 

(12) Heliotown Observatory, Lamy, NM 87540,

 

(13) LGM Radio Alachua, Alachua, FL 32615

 

(14) Easley, SC 29640

 

(15) Dalton State College, Dalton, GA 30720

 

 

 

 

 

Radio JOVE is a well-known public outreach, education, and citizen science project using radio astronomy and a hands-on radio telescope for science inquiry and education. Radio JOVE 2.0 is a new direction using radio spectrographs to provide a path for radio enthusiasts to grow into citizen scientists capable of operating their own radio observatory and providing science-quality data to an archive. Radio JOVE 2.0 uses more capable software defined radios (SDRs) and spectrograph recording software as a low-cost ($350) radio spectrograph that can address more science questions related to heliophysics, planetary and space weather science, and radio wave propagation. Our goals are: (1) Increase participant access and expand an existing radio spectrograph network, (2) Test and develop radio spectrograph hardware and software, (3) Upgrade the science capability of the data archive, and (4) Develop training modules to help people become citizen scientists. We will overview Radio JOVE 2.0 and give a short demonstration of the new radio spectrograph using the SDRplay RSP1A receiver with a dipole antenna and the associated Radio-Sky Spectrograph (RSS) software.

 

 

 

Identify proxies for the Schwabe cycle using Wilcox Solar Observatory data as a reference

 

Rodney Howe

 

Although the WSO data goes back to 1976 there is evidence that the polar solar field magnitudes and duration of each solar cycle cross-over would indicate the Schwabe cycle duration between solar cycles.

 

 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2012JA018320 This paper has two parts, the first is to show that north and south hemisphere visual observations do NOT represent the WSO polar field cross-overs. The second part uses the Poisson dispersion distribution of the total visual observations (Wolf numbers for the whole disk) to show a useful proxy for past Schwabe cycles.

 

 

 

Evaluating the Fast Folding Algorithm for Pulsar Detection

 

Dan Layne

 

 

 

The Fast Folding Algorithm (FFA) is a phase-coherent search method to detect periodic signals from pulsars. It has not often been used primarily because Fast Fourier Transform (FFT) methods, such as PRESTO, have been less computationally expensive. However, a recent FFA implementation called RIPTIDE makes efficient use of modern CPU cache architectures so that FFT methods no longer have a speed advantage. In theory, the FFA method is more sensitive than FFT methods, including for longer period pulsars and lower Signal-to-Noise Ratio (SNR). The frequency domain method PRESTO was not designed to be optimal at low SNR where amateurs tend to operate. In contrast, RIPTIDE directly folds data in the time domain and can produce good results at low SNR when PRESTO becomes ambiguous. This empirical study compares PRESTO with RIPTIDE for detecting known pulsars, especially at low SNR. The results show that PRESTO and RIPTIDE both give reliable results when SNR > 10. When SNR is between 4 and 10, both methods can produce acceptable results. When SNR is below 4, PRESTO becomes inconclusive while RIPTIDE can still produce acceptable results down to SNR of 2.7. RIPTIDE appears to be another tool that amateurs may use for detecting and confirming pulsars.

 

 

 

 

 

 

 

Real Time Position Control and Tracking System

 

For Altitude/Azimuth Mounts

 

Jack H. Lobingier

 

 

 

This presentation reviews the development of a closed-loop antenna positioning control and tracking system for any Altitude/Azimuth mount. It is designed for remote network operation and in addition allows for the control of other auxiliary functions, such as ENR Calibration signal insertion and 50 Ohm Load switching, Feed Head Focus Positioning, and Altitude/Azimuth beam position setting for the RadioSky.com “Radio Eyes” application. As implemented, it employs off-the-shelf electronics units and small Single Board Computer modules (SBCs). It is adaptable to any single Altitude/Azimuth mount with the proper selection of motors and positioners. The control software is written in Python3 and PyQt5, and although it is currently implemented in Linux, it should be executable in Windows with minor changes. Two previous articles have been published in the SARA Journals of September-October 2021 and March-April 2022, and a third is being submitted for inclusion into a future Journal. These three articles are used as background for this presentation.  

 

 

 

Kudos to the Noise!

 

TotalPower : a program for RF measures by using the low cost RTL-SDR dongle

 

Mario Natali

 

 

 

TotalPower is a multipurpose program that elaborates the RF signal captured via the low cost RTL-SDR dongle.

 

 

 

The main function is the representation of the RF signal both on a graph and on an analog meter. This function is very helpful in antenna pointing.

 

 

 

Another interesting function is the so called “Band explorer” mode that provides tools to analyze very low-level RF Noise. A dedicated configuration of this mode allows easy capture of H-Line.

 

 

 

The program, working in conjunction with the tracking program, PstRotator, can move directly antennas   and generate automatically noise maps of an arbitrary sky area. The RF noise data collected are passed to a very powerful 3D engine that allows several analyses including a contour plot.

 

 

 

All the functions will be illustrated, and a live recording will be shown

 

 

 

 

 

Comparing What We See With the "Scope-In-A-Box" and a 3.7 meter Antenna

 

Charles S. Osborne, K4CSO

 

 

 

In this presentation we will take a look at the SARA "Scope-In-A-Box" and a 3.7 Meter antenna using the same LNA and RTL-SDR to show how the two differ. Some noise figure test data on the Nooelec SAW Bird H1 LNAs and RTL-SDR will be discussed with a systems engineering view of how coax loss and component placement can affect system performance.  

 

 

 

 

 

The $300 SARA ‘Scope in a Box' Radio Telescope System and Beyond

 

>A beginner's introduction into receiving and processing 1.42 GHz RF emission signals from neutral hydrogen regions within the Milky Way <

 

Alex Petit

 

 

 

This presentation will briefly overview the history and value of radio astronomy. It will describe the Analog RF and Digital Signal hardware components and the basic software needed to acquire, process, and display the data.  Drift Scan data recording will be explained, and several upgrades will be suggested for improvements in signal amplitude and quality.

 

 

 

 

 

 

 

Improving IBT and IF Processor Performance

 

Bruce Randall NT4RT

 

 

 

The Itty Bitty Telescope (IBT) is a popular demonstration radio telescope. The IBT is not a serious astronomical instrument, but it does an excellent job of demonstrating what a radio telescope does. The weak link in this instrument is the “Satellite Finder” used for the IF and detector function.  This paper describes improvements to the IBT processor described in my June 2018 paper. 

 

 

 

Included is an improved Analog to Digital Converter and software improvements for the IBT processor.  Block diagrams, schematics, and Arduino source code will be made available.

 

 

 

Antenna aiming improvements using finders from optical telescopes are presented.

 

 

 

A possible calibration scheme is also discussed with the goal of getting repeatable sun and moon temperature measurements.

 

 

 

 

 

 

 

20M Telescope Demo: Raster Scans and Considerations

 

Steve Tzikas

 

 

 

       20m Project Updates

 

       20m Dish Demo

 

       20m Useful Comments

 

       Raster Scans and Considerations

 

       20m Observing Podcasts

 

       Contact and Open Forum

 

SARA Sections Update

 

Steve Tzikas

 

 

 

·         A browse through the SARA sections

 

  • Purpose of SARA Sections
  • Organization of SARA Sections
  • Volunteering
  • Section Coordinators
  • What’s New?
  • Suggested Ideas

 

 

 

Mitigating SAM-III Magnetometer Sensor Crosstalk

 

Whitham D. Reeve

 

 

 

The SAM-III, or Simple Aurora Monitor3-Axis, is an upgrade of the original 1- or 2-axis SAM and has been available since 2009. The SAM-III is used for geomagnetic observations and studies and as a geomagnetic disturbance monitor for aurora photography and amateur radio VHF communications.

 

When the signal outputs from two or three sensors are carried in the same cable to the SAM-III Controller, crosstalk interference can occur depending on the length and type of cable. The sensor outputs are unbalanced, and their signals easily couple into adjacent conductors and become part of the signals from other sensors.

 

The input circuits in the SAM-III Controller cannot distinguish between the interfering and actual signals. As a result, crosstalk manifests as noisy and inaccurate data and magnetogram traces. Unbalanced sensor signaling circuits also are susceptible to noise from other sources such as powerlines and radio transmission systems.

 

A robust crosstalk mitigation method is described in this paper including design, construction, and field installation. It uses interface circuitry at both ends of the sensor cable that converts the unbalanced sensor outputs to balanced circuits for transmission over inexpensive twisted pair cable. This method is based on the TIA-422 interface, which not only ensures sensor signal integrity but also allows the sensors to be installed much farther from the SAM-III Controller than possible with unbalanced circuits.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Receivers for a 2000 x 5m Radio Camera in Nevada

 

Dr. Sander Weinreb, L. D’Addario, J. Flygare, K. Shila, and J. Shi

 

 

 

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A radio telescope array with extraordinary sensitivity, resolution, and survey-speed is presently under design by the radio astronomy group at Caltech.  The array consists of 2000 fully-steerable paraboloidal 5m-diameter reflectors operating in the 700 MHz to 2000 MHz range, to be distributed in a 19 km x 15 km area in central Nevada. The array is a radio-camera in the sense that it   will provide images of most of the sky with 3.3 arcsecond resolution, and sensitivity of 0.5 micro-Janskies. It is expected that these images will observe 109 galaxies, 104 fast radio bursts, and 104 pulsars. The cost goal is $100M with a combination of public and private funds and completion by 2027.

 

The basic principle of the array is to measure the 4 million correlation cross  products of the 2000 antennas to form a  two-dimensional correlation function vs vector position on the earth surface. The 2-D Fourier transform of this correlation function is then the brightness image of the sky.

 

The major components of the array are:

 

1)      2000 hydroformed reflectors with system noise temperature of 25K

 

2)      Wideband, dual polarized feeds on each antenna

 

3)      4000 uncooled LNAs with 11K noise averaged of the frequency range

 

4)      Fiber optic, analog RF over fiber transmission of the signals from each antenna to a central correlator and image processing system.

 

5)      Digital filter bank processing of the 1300 MHz band into 0.1 MHz channels

 

6)      Cross-correlation of the 2000 antennas signals

 

7)      Fourier transformation of the correlation function to form the radio camera image.

 

The presentation will cover further details of the feeds, LNAs, and fiber optic transmission system.

 

 

 

 

 

 

 

 

 

 

 

 

 

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