Re: Visible Satellite Observations...

Allen Thomson (
Tue, 30 Nov 1999 08:16:04 -0600

----- Original Message -----
From: Torben Noerup Nielsen <torben@net.Hawaii.Edu>
To: Bruno Tilgner <>;
Sent: Tuesday, November 30, 1999 01:12 AM
Subject: Re: Visible Satellite Observations...

> >
> >While eclipsed, their radiation is mainly in the infrared. So you would
> >need an infrared telescope on a high mountaintop.
> I can deal with the high mountaintop. A real infrared telescope is a good
> deal harder due to the cost of the infrared arrays.
> >If you want to do daytime observations, you need a radar installation.
> >For nighttime observations photographic recordings (perhaps a modern
> >version of the Baker-Nunn camera) will give you accurate positions if
> >you can record the surrounding starfield, time marks and if you have
> >the necessary astrometric correction software (the easiest part).

> Well, that's what I was wondering about. According to the pictures at
>, it is indeed possible to get visual images during
> the daytime. I just haven't gotten enough information to know if I can get
> detection with a single image which is what I need since I want to record
> the position accurately.

Daytime detection and imaging of satellites in the visible and near to mid
IR is certainly possible. Whether you can get the positional accuracies you
need, I don't know, but two possibly useful references (there are probably
others) are:

"Ground-based electrooptical detection of artificial satellites in daylight
from reflected sunlight "
by E. Rork, S. Lin, A. Yakutis
Lincoln Laboratory, Massachusetts Institute of Technology, 1982

'Porog obnaruzheniia ISZ na dnevnom nebe' [Satellite detection threshold in
the daytime sky]
by B. Davydov
Kosmicheskie Issledovaniia, Vol. 28, Sept.-Oct. 1990
[I believe this appears in an English translation journal, but I don't have
the exact reference.]

If I remember aright, the basic conclusion in both is that fairly
straightforward daytime video detection can be done on satellites down to
visual magnitude 8 or so, and I'd assume that applies to field stars too,
maybe a bit brighter if you're tracking the satellite.

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