College of Science

Aaron Castellanos

Aaron Castellanos
Aaron with 3 of 42 antennas of the Allen Telescope Array (ATA). Hat Creek Radio Observatory. July 2012.

Aaron is an electrical engineering major concentrating in robotics and system controls and is also pursuing a physics minor with an emphasis in astrophysics. He spent the summer of 2012 working at the SETI Institute, as part of the CAMPARE program, writing java programs that better operate and collect/analyze data for the Allen Telescope Array, which is used to search for extraterrestrial intelligence and study the interstellar medium. Aaron hopes to build and program robotics used in planetary exploration. This is his story.

Sample graph: antenna 3. X and Y poles converge to a common system temperature. Good performing antenna.

In the Summer of 2012 I had the privilege to work at the SETI Institute under the mentorship of Dr. Gerry Harp, a trained quantum mechanic and the new director of the Center for SETI Research (one of three departments at SETI). Coming in I did not know what to expect. Grounded in an engineering background and going into a field primarily focused on astronomy/astrophysics was a little intimidating because my overall factual knowledge in this realm is quite minimal compared to the rest of the interns. This didn't stopped me though, in order to satisfy my curiosity of what exists in the universe I went in with an open mind, ready to absorb anything I could.

My project was a bit unordinary because it wasn't one large project I would work on all summer. It was several projects covering a wide range of functions all focusing on the collection and analysis of data, and telescope observations of the Allen Telescope Array (ATA) – a 42 radio antenna array located at the Hat Creek Radio Observatory five hours north of the SETI Institute. 

All the programs I wrote are in Java, which is a language I learned the first week I was working. The first program analyzed SETI data, collected over several months between 2009 and 2010. Its main function is to input a large data file from the ATA and conduct analysis in terms of computing the number of signals observed vs. the date and vs. the signal type. Signals that are observed go through a test process in order to determine whether they are Radio Frequency Interference (RFI) or extraterrestrial, and are characterized depending how many tests of uniqueness they pass.

The second program I built was the most important one. Its function is to input the gains of the signals received and compute the amplitude, phase and system temperature for all 42 antennas. This is used for automatic selection of the best antennas for observations and can optimize the tradeoff between fidelity and sensitivity with simple commands. The better the antenna, the better data we collect. I experimented with this new analysis tool by doing a month's observation on the galaxy 3c286, since it is above the horizon most of the day. Ideally this is to be run at the beginning of each day in order to analyze the array performance. A future application is image processing, which will be used to more efficiently clean images from man-made interference for higher resolution of the object being observed. The third program is considered the Master Operator because it does the process mentioned above autonomously and stores these system temperatures in a database, which are used for proceeding runs.

L to R: Jason (CPP), Rachel (Wellesley), and Aaron. SETI builds long lasting friendships.

I also had the opportunity to do a couple side projects, which consisted of analyzing the data of the solar eclipse collected on 5/20/2012 and analyzing the four months' worth of data of the Blazar 0716+714. 

Ultimately the summer was an amazing experience, from learning new things in astronomy and a real-world work environment, networking with new people and incredible peers, meeting personalities such as Bill Nye the Science Guy, and Jill Tarter (a world-famous alien hunter), traveling to new places, and attending events such as MSL's Curiosity landing on Mars at NASA's Ames Research Center. Most importantly, I am thrilled to have made a contribution to the search for extraterrestrial life in the universe, one of the greatest endeavors in the history of mankind.