Radio shields

Dear Mr. Radley,

I'm sorry about the late reply.
Were you at the International Space Development Conference on
Saturday 5/24? I'm
sorry if we missed each other or if my presentation was not up to
your expectation.

To partially answer your questions, please find a draft of my thesis
in progress at:
http://www.astro.gla.ac.uk/~yuki/YukiThesis.pdf

This will be revised significantly, but i'd appreciate any inputs!
Thanks!
-Yuki

--- In ssi_list@... "Charles Radley"
> 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
> > see
> > http://panic.millennium.berkeley.edu/~yu
kimoon/Takahashi-VLFA.doc
> >
> > I would really appreciate any feedback and suggestions from you.
> > Especially if you are in California, I hope to meet you soon!
> > Sincerely,
> > Yuki
> >
> > * * Yuki D. Takahashi + +
> > 0 0 \___/ UC Berkeley Physics Dept \___/ # #
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