[net.space] Holes in the Radio Sky

KING@KESTREL@sri-unix (07/27/82)

	I doubt that geosynchronous satellites cause any problems for
radio astronomers.  First, I assume designers of satellite systems
would have made the downlink frequencies ones that were quiet for
their own sakes.
	Second, the satellites are low enough so that if one radio
astronomy setup is disturbed, another will be able to pick up the
signal.
	Third, radio astronomers' targets are not stationary in the
sky.  Nor (as I understand it) does their equipment necessarily
require long, uninterrupted exposures.  It may merely be necessary to
snip out (say) seven second segments every four minutes.

smb (07/29/82)

Certain frequency bands are allocated by WARC (World Administrative Radio
Conference) for use by radio astronomers.  I seem to recall that there is
starting to be some problem about encroachment on these bands, though.


		Steve Bellovin
		duke!unc!smb
		smb.unc@udel-relay

Physics:hal (07/29/82)

    A geosynchronous satellite is stationary with respect to the Earth,
NOT with respect to the stars!  Thus, a given satellite will block a
radio telescopes view of a given area of the celestial sphere for a
limited time (once per day).

Hal Chambers
pur-ee!Physics:hal