2010 Western Conference at Stanford University

By: Whitham D. Reeve, Anchorage, Alaska USA

This summary is from my hand-written notes and includes numerous opinions of my own.

Approximately 32 people attended the SARA 2010 Western Conference at Stanford University in Stanford, California on March 20 and 21, 2010. Bill and Melinda Lord did a wonderful job of organizing the conference. Deborah Scherrer of Stanford University was our excellent and generous host and provided a conference room in the Physics/Astrophysics Building. There was plenty of good food and drinks and by all appearances and comments the conference was a great success.

Bill Lord, in his inimitable way, opened the conference and was quickly followed by Deborah Scherrer, who let us know that we had to keep the destruction of the facilities to a minimum or else we would get the bill. The university has strict polices against spilling coffee on the conference room carpet. Her warning helped because, as far as I know, there were no serious infractions and everyone left happy and nobody went to jail.

David Fields provided a quick overview of radio astronomy, emphasizing that amateur radio astronomers have many advantages over their professional colleagues, particularly in choosing projects and methods. It is too bad he provided only an abstract for the proceedings and not the full paper as this would have been good reference material.

From front to back, left to right- Wendy West, Jesse Sanderfer, Justin Medina, Keith Payea, Paul Shuch, Bruce Rout, Whitham Reeve, David Westman, Cameron Rout, Cliff Bates, Greg Bates, Roy Fobes, Wayne Watson, Dwight Sanderfer, Linda Fippin, Deborah Scherrer, Bob Lash, Steve Forney, Marcus Leech, Rich Rynne, Shad Nygren, Bill Lord, John Roberts , Ray Mitchell, Tim Huynh, Jim Moravec, David Fields, Ted Shelander, Curtis Kinghorn, Oscar Vera. Not pictured- Melinda Lord, Bill Shelander, Norm Galassi, Matt Ettus, Phillip Scherrer

We then had a very interesting presentation by Bruce Rout, in which he discussed his method for calculating the sizes of galaxies, among other things. He used NGC3198 as an example, putting forth his conclusions that it is “gravitationally self-bound in a linear mass distribution of constant linear density” and that, contrary to current thinking, it possesses no “dark matter.” Furthermore, the spiral nature of this galaxy (and other similar galaxies) appears that way to us because of our reference frame and the resulting delays in gravitational interaction. From a reference frame of the stars in NGC3198, the appearance would be different and the galaxy would appear as a linear mass distribution. Bruce discussed the relatively simple algebra, trigonometry and graphical methods he used to analyze the galaxy and draw these conclusions. He also provided a similar analysis for NGC4528. His conclusions were not accepted by all conference participants and a lively discussion followed in which one participant accused him of “hand-waving.” What is notable is that nobody actually refuted Bruce’s conclusions.

After Bill restored order and everyone calmed down, Phillip Scherrer discussed the Helioseismic and Magnetic Imager (HMI) that is on board the Solar Dynamics Observatory (SDO) space craft, which was being tested in its orbit as he spoke. The purpose of the HMI is to determine the Sun’s effect on Earth’s climate and enable prediction of space weather. We saw detailed animations and movies showing how the Sun works. Readers of this summary may want to access these online resources for additional information: sdo.gsfc.nasa.gov, hmi.standord.edu, lws.gshc.nasa.gov, and solar-center.stanford.edu.

Deborah Scherrer then talked about the SID, SuperSID and AWESOME VLF receivers used in the space weather monitoring programs. These are used to indirectly monitor solar flares by recording Sudden Ionospheric Disturbances caused by the flares. The original SID program uses a single-frequency VLF receiver designed by Ray Mitchell. The Stanford Solar Center has about 350 SID receivers deployed around the world (I have one in my observatory). The logistical challenges of worldwide deployment were astounding but largely overcome by persistence, patience and dedication. The AWESOME receiver is a much more expensive implementation of the SID receiver. The purposes of these programs are both education and research oriented. Stanford University acts as the repository for SID and AWESOME data.

Tim Huynh immediately followed Deborah with a description of the SuperSID VLF receiver. The SuperSID is available through SARA. It was designed as a lower-cost, yet more capable, replacement of the original SID receiver and takes advantage of technology that was not available when the SID was designed several years ago. Tim said he was inspired by the AAVSO VLF receiver’s simplicity. Instead of using a data logger, which was required with the original SID receiver, the SuperSID uses a PC soundcard and open-source (free) software to log, process and archive data. The receiver simultaneously receives multiple stations in a 48 kHz bandwidth. The SuperSID includes a set of manuals that were written to minimize the need for technical support (Question: What size wire should I use for the antenna? Answer: Read page xx of the manual).

Ray Mitchell, mentioned above, was SID Chief Engineer from 2003 to 2009. He added to Tim’s and Deborah’s talks by giving a short presentation on VLF propagation. Thus, between Deborah, Tim and Ray, we had an excellent and thorough overview of using VLF for monitoring solar flares.

After Ray finished, it was my turn to make a presentation. I discussed the UK Radio Astronomy Association (UKRAA) VLF receiver system. My talk was somewhat pedestrian, which, fortunately, did not detract from this very capable system. Although more expensive than the SuperSID, the modularized UKRAA VLF receiver may appeal to some amateur radio astronomers. It consists of a fairly small (0.4 m) square loop antenna, antenna tuning unit, and tunable receiver.

The last presentation of the day was by David Westman, who gave an enlightening talk on phased array interferometry, including a brief overview of interferometry theory and discussion of various arrays around the country. David gave the reasons for using interferometers: Increased resolution over a single dish antenna and avoidance of the mechanical and structural engineering problems associated with very large and heavy dish antennas. However, there are some tradeoffs, particularly in the need for complicated electronics to correlate the signals from multiple antennas and additional data processing to produce finished images. David provided a list of publicly available software packages that are used for array processing. He also mentioned an inexpensive yet excellent interferometry workshop called Synthesis Imaging Workshop at the NRAO facility in Socorro, New Mexico. This course has been presented every two years and the last one was in 2008.

That evening, many of us dined at the MacArthur Park Restaurant a few miles from our hotel. The food and accommodations were great. Melinda Lord provided accounting services and kept everyone honest. And the valet did not crash Bill and Melinda’s car (I was fortunate and appreciative to be hauled around by Bill and Melinda during the conference. Bill said, “Whit, assume your position” whenever we needed to go somewhere).

David Fields was first up the next day. He provided an update on the Moby Dish Project, combining the name of the big white whale and a large (4.5 m) white dish antenna. Accompanying the antenna is a camper that was setup to hold the electronic equipment, appropriately called the Pequod and partially destroyed in a wind storm (but later repaired). David also discussed a project that detects meteors through the scattering and reflection of FM broadcast station signals (~100 MHz) off the ionized trails of meteors as they enter the Earth’s atmosphere. The distance between the receiver and transmitter should be around 90-100 miles. It was suggested by an audience member (name not recorded) that signals in the VHF aircraft navigation band (108 – 118 MHz) also can be used for this purpose because the transmitters are always on.

An open forum followed. Keith Payea gave a brief description of his projects in the VLF, LF, HF and VHF frequency ranges. More information can be found at: www.bryantlabs.net. Cliff Bates mentioned that weather telemetry transmitters in the 52-55 MHz band can be used for meteor scatter experiments. He uses a preamplifier, scanner and soundcard with a spectrograph/waterfall display program such as SETIFOX. Ray Fobes discussed his application of the Universal Software Radio Peripheral (USRP) at Prescott, Arizona. Paul Shuch briefly discussed his “off-the-wall” idea of making a single-dish interferometer out of a Ku-band dish antenna that has three Low-Noise Block down-converter (LNB) feeds. He said he would try it out and we hope he will report his results in the SARA Journal. Justin Medina, Jared Lemons and Wendy West, three high-school students from Colorado, discussed their projects working with and developing optical/radio observatories. Wendy described her idea to build a heart-shaped loop antenna for use with the SuperSID receiver. She also provided considerable advice on how to encourage young people to participate in science.

The next scheduled talk was by Bob Lash, who provided an update on Bob And Mike’s Big Investment (BAMBI). This is a two-dish interferometer where the dish antennas are separated by about 1000 miles. Unfortunately, one of the antennas was destroyed in a storm and gophers continue to damage antenna and control cables on the other one. However, the serviceable dish was able to detect Sagittarius A, Cassiopeia A, Cygnus A and the Comet Shoemaker-Levi impact on Jupiter.

Deborah Scherrer then discussed mentor training for the SuperSID program, and in particular advice on how to help teachers and students get a SuperSID working. A spirited discussion followed with comments by the audience on the many difficulties they have motivating young people to not only think about science but to just plain think.

Our last scheduled talk was by Marcus Leech, who discussed a modular software system he has developed, which is similar to National Instruments LabVIEW and Matlab but for radio astronomy applications. As you would suspect, the system requires some hardware - Gnu Radio – but also includes Integrated Radio Astronomy (IRA) and other software applications. The software is freely available and can be used with software defined radios from VLF to UHF.

We had a period of open discussion and heard once again from Cliff Bates. He had hard-earned experience and gave advice for amateur radio astronomers pursuing Earth-Moon-Earth (EME) projects: Get the biggest dish antenna you can find and then use the biggest thrust bearing you can get for turning the antenna. He uses a 3 ft. diameter bearing from an old electric utility bucket truck. Shad Nygren was our last unscheduled speaker. He described using the AntennaCraft U4000 and U8000 dipole arrays, originally designed for the UHF television band. He suggested using channel 37, which covers the 6 MHz band from 608-614 MHz and has been allocated for radio astronomy purposes. His plan is to build an array of arrays using these antennas. We hope to hear back from him on this project.

We then left for a tour of Stanford University’s 150 ft diameter dish antenna on the hill above the university (Stanford University Radio Science Field site). This is a massive structure weighing 300,000 lbs. After considerable delay due to being locked out of the site, we finally gained access and met the site manager at the dish. He had worked there many years and related some humorous stories (in retrospect) including an incident in which a fire started in the waveguide carrying 40,000 watts of RF from the transmitter output and another when an expert used a hammer to fix an open filament in the transmitter klystron during a critical mission. We also toured several other radio sites in the vicinity, and there were many of them.

On Ray Mitchell’s recommendation, many of us met at the Fish Market Restaurant for dinner. This restaurant serves fresh seafood caught that day by its own fishing boat fleet. We had good service and enjoyed the evening.

The next day, Monday, David Westman organized a tour of the SETI Institute but I was on an airplane headed home by that time and missed it.

To see pictures from the conference and tours http://www.flickr.com/photos/tnskynet/sets/72157623695301452/