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2013 Annual Conference Abstracts
The following papers will be presented at the annual conference at NRAO in Green Bank, WV. Check back for late additions.
Dr. Dan Reichart earned B.S. degrees in Astronomy & Astrophysics, Physics, and Mathematics and a minor in History from the Pennsylvania State University in 1996, and M.S. and Ph.D. degrees in Astronomy & Astrophysics from the University of Chicago in 1998 and 2000. Dan then won a Hubble Postdoctoral Fellowship, which he took to the California Institute of Technology in Pasadena. Since 2002, he has been an Assistant Professor of Physics & Astronomy at the University of North Carolina at Chapel Hill.
Dan’s dissertation research on distant, cosmic explosions called gamma-ray bursts was ranked by Science Magazine as one of the top ten discoveries in science in 1999, and in 2003 earned him the Robert J. Trumpler Award, for top astrophysics dissertation research in North America.
In 2005, he and his students at the University of North Carolina discovered the most distant explosion in the universe yet known, a gamma-ray burst that occurred 12.8 billion years ago, when the universe was only 6% its current age. Their findings were published in Nature Magazine.
Dan and his students are currently building six robotic telescopes, or telescopes that control themselves, on a remote mountaintop in the Chilean Andes, and are helping others to build similar telescopes across the United States. When not observing gamma-ray bursts, the telescopes are available to students and educators of all levels from their home and school computers.
Dan is also the recipient of the Carl Sagan Award for Excellence in Teaching, the Nathan Sugarman Award for Excellence in Research, the Donn MacMinn Award for Service beyond the Walls of the University, and Ernest F. Fullam Award of Dudley Observatory.
As of June 2006, he has published 60 scientific papers, 114 observing reports, and has written popular articles for Sky & Telescope and Mercury magazines. He has raised over two million dollars for his research, and regularly reviews grant proposals for the National Science Foundation and NASA.
RASDR 2062: 200 Years of Receiver Evolution
By: D. Fields2, P. Oxley, B. Vacaliuc, S. Kurtz , J. Kruth, C. Lyster and R. Jain
Decades of experimental studies led physicist James Clerk Maxwell to formulate the theoretical foundations of electromagnetic energy in 1862. Thirty years later, another physicist, Henrich Hertz, demonstrated radio transmission and reception and initiated an era of Hardware-Defined Receivers (HDR). Receivers in the span of 150 years evolved from having a design focus in hardware, to a design focus in software, as Software Defined Receivers (SDR) began a 20-y rise to dominance. SDR that is optimized for Radio Astronomy, RASDR, consists of a minimalist front end and a software-driven (gate logic arrays and desktop computer) back end. This software-rich back end performs the signal processing required to cope with different types of modulation and to resolve/present low S/N data. RASDR is functioning in benchtop mode with multi-modulation detection capability from 0.0001 to 3.84 GHz. Current RASDR software performs some basic parameter optimizations, but the SDR software is basically static within an observing session.
Beyond the SDR design focus lies the Algorithm Defined Receiver4 (ADR) in which software will evolve based on signals detected and project goals. Project goals will eventually relate to radio astronomy research, but they are not now driven by scientific considerations. Instead, they are driven by military and commercial interests. Recent DARPA design challenges, cryptoanalysis problems, and multi-million dollar prizes offered by commercial interests and claimed by dedicated software groups now dominate algorithm development.
RASDR 2062 will be an ADR that copes with changing in signal structure, interference from natural and other sources, and the probable detection of new forms of signal modulation that arise frequently in basic research and that may be found in SETI (Search for Extraterrestrial Intelligence). Such applications require an ADR defined by evolving software having a flexible, purpose-driven algorithm structure.
Utilizing Standard Offset Gregorian Broadband Feed Antennas as a Building Block for Future SARA Projects
By: Mohammad Hassan
The age of mass produced antennas is coming to radio astronomy, leading to the construction of powerful and flexible broadband radio telescope systems covering the low noise microwave region between 1 – 10 GHz in a single feed and cooled amplifier design.
Such a single antenna configuration can make it attractive for worldwide university based educational radio astronomy projects, where simultaneous observations over a number of frequencies within the specified range can be made possible. SARA might as well consider utilizing recently developed subsystem hardware to promote and perhaps spearhead some basic interferometer designs, reviving what Robert Sickels initiated some 30 years ago.
A basic four element dual polarization interferometer system can be considered, based on the 21 ft offset Gregorian antennas that are being used in the Allen Telescope Array. Such a system can be utilized in widely spread geographical areas in CONUS as well as internationally. The possibility of connecting a number of widely spread four element systems can become a reality in the future utilizing single mass produced blocks.
Standard manufactured ATA FX8 correlator cards could be utilized for certain projects. Finally one might consider moon phase measurements with a 2000 ft baseline at 5 GHz, which could be attractive to a number of institutions in the Middle East and Asia, as well as extending such measurements done at Roane State to the radio spectrum, while developing their RASDR into broadband applications with a single antenna and feed.
By Ciprian Sufitchi N2YO
Arduino is an open-source microcontroller platform based on flexible, inexpensive, easy-to-use hardware and software. It has an infinite number of applications, and some of them may include data processing and automation for radio astronomy projects. One practical example is the SID monitor. In order to retrieve and store the output from this receiver, an A/D converter and a computer are required. With Arduino Uno, a microSD shield, and some code written in C, the system ("SIDruino") becomes a cheap, light, low power and portable VLF monitor.
“Beyond RadioJOVE: a Case for a COSMIC Paradigm Shift to Invent New Technologies for Old Haunts and Embrace a Community-based, All-Wavelength Funding Model that Showcases Small Instruments and Linked Research Agendas”
By William F. Vartorella, Ph.D., C.B.C.
We live in what Jason Pontin has characterized as an age of “Irreducible Complexities,” particularly within the context of space exploration. This is underscored by plunging budgets and conflicting long-range vision by governmental programs to support and expand radio astronomy, particularly to the public, who seemingly perceive it as esoteric squiggly lines scratched on an incomprehensible graph. The dichotomy is best posed by Shunryu Suzuki: “In the beginner’s mind there are many possibilities, but in the expert’s there are few.” This paper takes these two perspectives and spins them into a paradigm shift called COSMIC. We choose this acronym in homage to the accidental discovery of cosmic radio emissions, stumbled upon by radio amateurs while developing shortwave communications.
COSMIC, which stands for Community Observatories and a Symbiotic, Multi-disciplinary, Inventive Colloquia, is a disruptive model for re-purposing abandoned or under-utilized small institutional observatories on a cooperative, public, all-wavelength basis. Projects pioneered by RadioJOVE and SuperSID, aided by the Internet of Things, provide a funding platform capable of sparking public interest and attracting small grants from the array of family and community foundations with a STEM science or education focus. The trick: tie languishing astronomy programs and optical instruments to the new wave personified by commercial space’s smaller, faster, cheaper model of exploration.
NanoRacks has already fostered a business model that enables even high school science classes to fly affordable experiments on ISS. ARISS has successfully linked excited students to “ham radio astronauts” aboard ISS, with a requirement of considerable research and community participation by selected institutions. Small, inexpensive radio astronomy instruments, pioneered by SARA, et al., could become a bridge enabling struggling observatories to provide communities a new window on space exploration. This paper presents proven strategies and tactics for funding science and exploration of the cosmos using the crucible of small radio astronomy as a linked public gateway to big ideas.
A Software Lock-In Amplifier
By Bruce Randall NT4RT
A Lock-In amplifier is sometimes used for signal processing in the Dicke Switch receiver and in the Phase Switched Interferometer. A software Lock-In amplifier was developed for the Windows™ operating system that uses the computer sound board for the ADC and DAC functions. Programming was done in C Sharp programming language. The free C Sharp compiler available from Microsoft™ was used to compile code. Both executable files and source code will be available for conference attendees.
Using a Scanner Receiver in a 408MHz Phase Switched Interferometer
By: Bruce Randall NT4RT
A slightly modified Uniden SC150 hand held scanner is used to do most of the RF signal processing for a phase switched interferometer. A software based Lock-In Amplifier is used for the low frequency signal processing.
The author has some number of these SC150 scanners, with plans to distribute them to SARA members after the modifications are made. It is hoped that people of minimal technical skills will be able to put together a working radio telescope.
Observations of Jovian Emissions by Multiple Spaced Radio Spectrographs: from Jim Brown, Hawk’s Nest Radio Astronomy Observatory
By: Jim Brown, HNRAO, Richard Flagg, WCCRO, Wes Greenman, LGM Radio Alachua, Dave Typinski, AJ4CO Observatory, Andrew Mount, MRAO
We describe observations of Jovian decametric emissions using radio spectrographs operating simultaneous at several geographic locations. At times signals appear similar to one another on spectrograms from different observatories. At other times signals received at one or more observatories appear very different from one another. Frequently, signals received at one observatory may not even be detected at other locations. Variations in signal strength and structure are likely caused by ionospheric effects as well as propagation effects in the interplanetary medium.
SuperSID v3.0 Receiver and SuperSID Test Setup Generator (Comberator)
By:Tom Hagen and Ken Redcap
This paper covers two subjects, the development of a new SuperSID pre-amp (version 3.0) and the development of a SuperSID system test generator called the Comberator The existing SuperSID v2.0 pre-amp is powered by a SARA-supplied external power supply. Among other problems, the SuperSID’s are being shipped worldwide and the AC mains supply differences need to be taken into consideration. To eliminate the external supply, the v3.0 SuperSID pre-amp will obtain 5VDC power from the USB port. In addition, for cost reduction, surface mount parts are used. Stanford originally did this design and at this point a new PCB has been fabricated and is being tested. The second part of the paper deals with a SuperSID test generator system test generator that we’re calling the Comberator. The late Dave Benham and Tom Hagen started this project and with Dave's passing Bill Lord and Tom are continuing the work. The problem that needs to be addressed is that many people worldwide have been having problems setting up their SuperSID systems and a simple test generator is being developed to assist in solving these problems. The generator will allow users to break the setup down into individual pieces that can be tested in a step-by-step fashion.
Building a low cost IBT
By: Tom Crowley
The IBT has been around for several years, with several implementations. This paper will discuss building a low cost IBT that can use a PC sound card for data collection using the very popular Sky-Pipe software by Jim Sky. A review of a few of the experiments that may be done with the IBT will be discussed. Methods for increasing the gain of the system will also be introduced.
By: Paul Oxley
An update of the RASDR project will be presented along with Windows control of the wide Spectral range of the RASDR and use of USB to provide a high speed interface to the RASDR hardware.
RASDRWin is a Windows based platform that provides the control and data analysis for the RASDR system. It is written in C to allow portability across Windows, Linux and Mac-OS. The portability is maintained by avoiding graphical user interfaces that are specific to each platform. The use of C also provides the high speed processing necessary for data analysis at the RASDR rates (28.8 M Samples per Second Maximum.
The control portion of RASDRWin provides the user the capability of configuring and optimizing the LIME chip on the RASDR boards. This includes the DC calibration of the Chip stages, minimizing second order intermodulation and optimal gain, bandwidth and sample rate selection to meet the user’s needs.
A portion of the code also provides user control of the capability to lock the sample clock and local oscillators to a standard reference such as a GPS receiver.
The analysis capabilities include an interface to Spectrum Labs software, a single snapshot interface to MS-Excel for display and FFT calculation, and a capability to produce multiple spectral line spreadsheets that are decimated to the user’s desired sample rate and integrated over a user specified period. The decimation rates can be any power of 2 fraction of the inherent sample rate on the board being controlled. The integration period is user variable from 1 second to 3600 seconds. The raw sample data can also be directed to a binary file for post collection processing. This capability also manages the amount of user’s disk space being consumed to avoid over filling a disk.
A Tale of Two Receivers: BladeRF and DigiRed are high-performance RASDR 2 receivers for radio astronomy use
By: Bogdan Vacaliuc
SARA - Melinda Lord - Editor
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