Radio shields

Yuki,

Thanks for your reply. FYI I am in Oregon, USA.

I have a few more questions if you can help.

What are the frequency ranges of interest ?

What must be the minimum diameter of the shield, assuming it is a disk
behind the telescope dish ?

Do we need to consider diffraction cones of RF around the edge of the shield
on to the receiver element(s) ?

It would seem that due to the high cost of soft landing equipment on to the
surface of the Moon, that a shielded radio telescope in space could givei
similar performance at much lower cost.

What do you think ?

Sincerely,

Charles F. Radley

>
> Message: 1
> Date: Mon, 28 Apr 2003 21:20:45 -0000
>
> I have not come across any analysis on space-based radio shield yet...
> From my understanding (i'm still a beginner in this field), i'd guess that
the
> thickness of the shield should go up as the square-root of the observing
> wavelength. For example, using an aluminum shield, attennuating a 100-
> MHz wave by N orders of magnitude in power will require a thickness of
~8*N
> micron. Anyhow, for frequencies below 30 MHz (wavelengths over 10 m), a
> single dish (even a 100-meter one) will not provide very useful angular
> resolutions.
>
> My proposal in view of the high cost of building a telescope on the lunar
far
> side is to begin with a precursor observatory at the lunar south pole.
Please