Wednesday, June 27, 2007

BITS Goa Radio Telescope

when i spoke about our plans for hardware for our radio telescope, there was some feedback from my supervisor (Deshpande, RRI). he was of the opinion, that

  1. our telescope was a fantastic idea, and could eventually do international science using 4 element dipoles. we have to plan and execute it well, of course.

  2. in the beginning, we could make images using 2 antennas only, with Mandar and Aniket's data acquisition cards. this means, as soon as we demonstrate 2-slit interferometer, we can think of maps in the second semester.

  3. we should think of using 2 bits and less bandwidth. eventually, we will have 4 element dipoles. so, we will have to store 4x2 = 8 bits = 1 byte at nyquist rate. if we opt for smaller bandwidth (0.25 MHz), we could be saving 0.5 MBytes per second on the disk, with each byte being a sample each from 4 elements.

  4. In the immediate plans:

  5. we should converge using "Mini Circuits" ICs for our RF components. See their website

  6. also, for LO stability, either

    a) opt for GPS receiver, and use its 10 MHz signal for LO

    b) use a "oven controlled crystal oscillator"

    the second option is better for us for now. we will continue to explore the second option for better eventual stability of frequency signal. for better mapping, we need our sampler and LO to be really stable.


Anonymous said...

Hello Sir, A compulsory comment for not allowing anonymous comments-
1)Not everyone wants to sign-in just to post a comment. 2)You cant mention your blog, so there is loss of an incentive (and not everyone blogs on blogger). 3)There may be reasons for anonymous comments!

Your have me as a reader! Also, I guess 'sir' looks odd so I'd skip it from the next time.

myopic astronomer said...


Wherever you are right now, hi. Today I stopped anon comments, since they swamped the blog posts everywhere with $hitty ads.

I hope you comment, though.