I am a Senior Software Engineer at the SETI Institute concentrating on detecting SETI signals using the Allen Telescope Array. I am an expert in computer software development, I am comfortable developing in many programming languages and many different types of computer systems. My past work has involved a lot of hardware design and development, tying hardware and software to networks and the internet. Since 2008 I have been trying to continually build my skills and knowlege of digital signal processing and trying to master the Allen Telescope Array hardware and software.
I work on the Allen Telescope Array (ATA) software and hardware control systems. I do it all. I plan and implement the observing schedule. I develop and maintain the SETI search software. I am also trying to improve the SETI system at the ATA and find new uses for this wonderful instrument.
The development and maintaining involves improving the software that operates the 42 - 6 meter receiving dishes at the ATA, maintaining and developing electronic controls, and developing/improving the software that analyzes the received data for signals. I spend several days on site at the ATA every month. I wish I could be there more.
Every night we observe for 12 hours. I have a web site that shows the details of the observing schedule and will show real-time observation status when observing. Please visit http://setiquest.info
When observing the system commonly sees a lot of signals. Our software system judges the detected signals and tries to determine if this is actually a signal of interest. I publish plots of all the signals we see every night. See http://setiquest.info/mlfiles2 to look a the signal plots, updated every morning after observing. Most are boring static, but occasionally there is a weird one.
We represent our signal data visually in the form of "waterfall" plots that you will bee below. Basically they are plots of time on the Y axis, frequency on the X axis, and the brightness is the signal strength.
Here are some examples of the types of signals we commonly see and determine are Radio Frequency Interference (RFI).
We call this one a squiggle. We see a lot of these. It is probably the result of an oscillator frequency that is unstable. Maybe from an old piece of equipment.
This is some type of spacecraft that is turning a corner, the change in frequency is changing due to the Doppler effect.
This is a signal from a satellite, looks like a slinky. We get a lot of weird shapes.
Recently I have been testing the system to see if we can detect known signals. The only appropriate signals that I know of would be coming from spacecraft such as Voyager1 (Voyager2 is always below the ATA horizon) or the probes around Mars and Saturn. Weekly I try to see if I can detect the carrier signal from several spacecraft on my list. Sometimes they are not transmitting, but often I see them.
Here is an example of seeing Voyager1. The transmitter on Voyager1 is very weak and it is far away, they say outside the actual solar system. Since the signal is very weak, the signal line in the waterfall is very dim. Even though it is weak, our system easily detects it and reports that this is a signal of interest.
Here is the Cassini spacecraft orbiting around Saturn. This was detected for the first time by the ATA on September 03, 2014. Note the signal is much stronger than Voyager1.
Recently we were part of the ISEE3 Reboot Project. I have been trying to receive and record the data with enough quality for decoding the signals. But recently the signal has not been detectable. It is suspected either the ISEE3 stopped transmitting or it has tilted the antennas off just enough from pointing to the Earth.
Another capability of the Allen Telescope Array is its correlator. With the correlator you do not search for signals. Instead, it is basically like a camera that operates int the radio spectrum. With the correlator we can create images of things in the sky that are not visible to the human eye.
Here is an example of an image I took with the correlator of Cassiopeia A, the brightest extrasolar radio source in the sky above 1GHz. The image on the left is from the ATA and as a comparison on the right is a composit from various instruments. The ATA compares pretty well to much more complicated and vastly more expensive instruments.