Abstracts for 2017 Western Conference in Socorro, NM
Abstracts for 2017 Western Conference in Socorro, NM
Introduction to Amateur Radio Astronomy
Ed Harfmann
This is the same Introduction to Radio Astronomy presentation as the one given at the Eastern conference at Green Bank for the past two years. Starting with a brief history of astronomy, it builds upon that to show first how radio astronomy is the same, then different from astronomy. A brief history of radio astronomy follows marking a few of the turning points that took it from something that was deemed superfluous to a critical tool in modern astronomy and cosmology. Following this, the presentation gives a brief tour of professional facilities and then of the projects supported by SARA.
Five Projects for the Astronomical League’s Radio Astronomy Observation Program.
Dr. Alex Vrenios
The Astronomical League recently introduced a Radio Astronomy Observing Program, requiring its members to complete four of five observing projects: detecting solar radiation, sudden ionospheric disturbances (SIDs), Jupiter’s radio storms, meteor scatter and galactic hydrogen radiation. This paper describes my experience with each of these projects, and the development of a modest but working radio telescope along the way.
Radio Astronomy CubeSats - Anthology
Professor J. Wayne McCain, Collin R. McCain (student)
CubeSats – have been around for upwards of two decades now. The terminology refers to small,
light-weight, and usually ‘cube-shaped’ secondary payload satellites that take advantage of today’s
electronics to accomplish useful scientific research in space at much reduced cost and complexity. CubeSats are miniaturized satellites originally designed for use in conjunction with university educational projects and are typically 10 cm x 10 cm x 10 cm (4 inches x 4 inches x 4 inches) and approximately 1.3 kg (3 lbs).The CubeSat reference design was first proposed in 1999 by professors from California Polytechnic State University and Bob Twiggs of Stanford University (formerly Weber State (Utah)). Their goal was to enable graduate students to be able to design, build, test and operate in space a small spacecraft with capabilities similar to that of the very first spacecraft, Sputnik. The CubeSat, as initially proposed, did not set out to become a standard; rather, it became a standard over time. The first batch of CubeSats was launched in June 2003 on a Russian Eurockot vehicle. One launch provider, ULA (United Launch Alliance, Decatur, AL), has successfully placed over 100 into orbit by year’s end, 2016. Significant numbers of these small spacecraft have been dedicated to radio-astronomy-related research. This paper emphasizes and lists those cubesat missions (past-present-
near future) that have radio astronomy research objectives. It also formulates a basic specification for
a possible SARA-initiated cubesat radio astronomy mission (SARA-SAT1) and provides a list of potential mission objectives/scenarios for consideration. By Dr. J. Wayne McCain – (256-216-5369) – drwayne@athens.edu.
Instrumentation Section Report - RASDR
Bogdan Vacaliuc
The electronics and instrumentation section is dedicated towards informing the membership of the advances in components and techniques that are available to them for use in their projects. The section provides introductory information as well as links to curated technical documents, specifications and software that can be used to successfully assemble radio telescopes over a wide variety of wavelengths. Recent updates to the section data will be highlighted in this talk as well as a short update on the current state of the Radio Astronomy Software Defined Receiver (RASDR) project.
A 21cm Band Downconverter System
Stuart Rumley
The purpose of this project was to develop and manufacture a reproducible, high performance downconverter that can serve as the front-end for a radio astronomy (RA) and SETI receiver system in the 21cm band. The current practice is to use either a high-performance direct-downconverter fast A-D module or a low-cost TV-tuner based dongle. It is proposed that a better solution is to use a downconverter system to allow the use of any low cost software defined receiver (SDR) capable of tuning 0~30MHz. The downconverter was developed utilizing low-cost, no-tune, ceramic dielectric filters for superior interference rejection while still providing a 0.3dB noise figure. By providing 40dB of overall gain and well defined bandpass, this downconverter can then be antenna mounted and used with a number of 30MHz SDRs to provide a high performance radio astronomy receiver.
Pulsar Observations at 1400 MHz using the 40-ft Telescope at the GBO
Skip Crilly
Pulsar observations at 1400 MHz are difficult to make with small apertures due to lowering flux at increasing frequency. This paper describes a pulsar back-end measurement system that was designed to be used with the Forty Foot Telescope at the Green Bank Observatory. The system observes pulsars using the overlap and add method, with known pulsar period. Pulsar observations and the pulsar measurement system will be described, with information provided so that others may replicate the measurement system at reasonably low cost.
Receiver Stability Analysis, Concepts and Measurements
Whitham D. Reeve
The emissions received from many celestial radio sources are indistinguishable from the random noise generated by the receiver system itself, in fact they can be substantially lower than the receiver noise. The effect of the celestial source is to increase the already existing noise by a small amount. Detecting such small changes requires that the observed power is averaged or integrated over time. However, increasing detection sensitivity by averaging is only effective for certain types of noise. In particular, the receiver noise must be Gaussian or close to Gaussian. Gaussian noise is a category of noise also called white frequency modulation, or white FM, noise and often colloquially called pure noise. White FM noise has a flat spectrum over the frequency range of interest and, in the time domain, the noise has random amplitudes with zero average.
During relatively long observations, the receiver’s averaged output eventually starts to drift and different types of non-Gaussian noise dominate the output. Beyond this point continued averaging does not reduce the noise fluctuation and instead may increase it, thus reducing rather than increasing the system sensitivity. The problem for a given system and set of conditions is to determine the longest averaging interval that is effective for reducing the noise effects.
Amateur radio astronomers often use total power receivers because of their relative simplicity. The stability of a total power receiver determines how long its output may be averaged. Receiver stability can be measured and analyzed by terminating its RF input with a resistive termination or stable noise generator, regularly sampling the receiver output and then computing and plotting a statistical property of the samples called the Allan Deviation.
In Part I of this paper I discuss the basic characteristics of total power receivers and the Allan Deviation calculations that may be used to analyze receiver stability. In Part II I discuss measurement methods and provide stability measurements for several common receivers used in amateur radio astronomy. I also include similar measurements for soundcards because they are used with analog narrowband receivers and can potentially dominate the statistical properties of the output data. Part II focuses on receivers operating in the high frequency (HF) band, particularly the upper portion from 15 to 30 MHz. However, the concepts and measurement methods apply to any total power receiver at any frequency. The information presented here may help readers measure the maximum averaging times for their receiver systems.
Commissioning a SAM-III magnetometer
Keith Payea
This paper describes the construction of a SAM-III magnetometer at the author’s location in a suburban location in Northern California. Inspiration for this project came from a talk given by Whitham Reeve at the 2016 SARA Western Conference. The SAM-III Magnetometer kit is well documented and provides an excellent starting point, but each installation has unique challenges which must be overcome. In this paper I will describe some of my solutions to the challenges and progress to date. Some of the key points are:
· Providing a stable environment for the sensors given the large day/night temperature swings in the area.
· Protecting the sensors and supporting equipment from the elements and insects
· Transmitting power and signals over a long distance.
· Correlation between data from my magnetometer and those of the USGS
Plishner Radio Astronomy and Space Science Center talks:
The Use of Statistical Process Control to Improve the
Detection of Extraterrestrial Radio Sources
Richard Russel
Deep Space Exploration Society
The Plishner Radio Astronomy and Space Science Center is operated by the Deep Space Exploration Society based out of Colorado Springs, Colorado. The largest antenna system is a 60 ft. parabolic reflector. This paper describes the use of statistical process control to troubleshoot the prototype UHF radio telescope and enhance the detection of weak radio sources.
60-Foot Dish Position Indication System Development
David Molter, Glenn Davis, Richard Russel
Deep Space Exploration Society
The Plishner Radio Astronomy and Space Science Center is operated by the Deep Space Exploration Society based out of Colorado Springs, Colorado. The largest antenna system is a 60 ft. parabolic reflector. This paper describes the development of a position indication system that enables precision pointing for radio astronomy experiments as well as Earth-Moon-Earth and tropospheric communications at 1296 MHZ, 432 MHz and 144 MHz frequencies.
Efficiency Analysis of the Plishner Radio Astronomy and Science Center
Solar Power Systems
Bill Miller
Deep Space Exploration Society
The Plishner Radio Astronomy and Space Science Center is operated by the Deep Space Exploration Society based out of Colorado Springs, Colorado. The largest antenna system is a 60 ft. parabolic reflector. The site is usually unmanned and completely off the power grid. The site is powered with a propane generator when occupied and a random collection of solar panels and batteries when unoccupied. Analysis of the available power system capacities and site solar insolation provides insight for modeling to determine the total power available for the remote computers and radio astronomy receiver systems.