Surplus PrimeStar Dishes => Radio Telescope Array?

Sean Clifford asks: "Anyone have suggestions on how to get started setting up an amateur radio telescope array using a ton of old PrimeStar dishes? I've read a couple of articles like this one, that makes this idea seem good in theory. Adapting some gear for RVs to steer the dishes should be simple, but does anyone know of good open source software for controlling them? And *nix software for collecting, filtering, and analyzing the data would be sweet too. I've got a couple of hundred dishes in the back yard at work that are screaming for some type of use other than recycling. I'm already adapting a couple for a wireless network, but would like to see what I can do with the rest."

Comments

Have you tried...

[Usquebaugh]

The SARA, ARRL or DX zone. You've probably done the google search for "amateur radio telescope"
Given that you have the hardware it would seem you need to find someone who has the skills to design the thing. My guess is that your local ham or astrology club would have people who have the knowledge and desire to help. Do you have a university close by, prehaps they might want to take it on as a grad project. But my first port of call would be SARA.
IMHO this is the sort of question that /. should post, I doubt there will be many posts but who cares. I want thought provoking or interesting questions. In short I want questions that make me go and hunt down some ideas.

Phasing

[Detritus]

I'm not an RF guy, but I work around microwave antennas and receivers. Combining multiple feeds, from one antenna or multiple antennas, is tricky, esp. at microwave frequencies. For the frequency of interest, the feeds must be in phase with each other. You need to be able to adjust the phasing for maximum output from the combiner. If you want to do interferometry, it gets a lot more complicated.

Bandwidth

[Technician]

Bandwidth of the dishes is going to be a problem. Much of the search is in the 150 MHZ and up spectrum. The smaller dishes can not focus a signal much larger than 10 cM. They are limited mostly to the microwave band above 1GHZ. They will not work well in the 100 Mhz to 1GHZ band. Phasing an array for a large effective apature is not childs play at these frequencies. Temprature changes change the geometry of the feedlines. Microwaves have a very high attenuation in coax. To get past just these limitations would almost require downconverting. To maintain signal phase, the downconversion would have to be done with very low jitter phase locked downconverters tied to a master clock. Last time I checked a phase locked downconverter was >$1200.00 US. (I installed one for a radio station to receive a subscription CANA feed on C-band)