Re: List of Bright Satellites - Why is it prepared Manually?

Bjoern Gimle (
Sun, 15 Dec 1996 14:49:06 +0100 (MET)

>Patrick Wiggins
>> Greetings!
>> 	A few days back I posted a request for information on satellites 
>> visible from mildly light polluted skies with the naked eye.

Robert Sheaffer :
>Am I alone in thinking that this is a cart-before-the-horse approach?
>In other words, "figure out a list of satellites we might be able to
>see, then run them through prediction software to see which ones turn
>I am wondering why, with all of the satellite-prediction software
>we have today, it is still necessary to ask this question, especially
>since magnitude estimates can be found in Ted Molczan's elements
>file. Why doesn't one of these programs simply run through the
>elements list, calculate a predicted magnitude, and if it shows
>up brighter than a predicted magnitude, print it out? So far as
>I know, only QUICKSAT does something close to this. However, it
>uses its own file of predicted magnitudes which are actually
>'greatest ever' brightness rather than 'expected' brightness,
>which results in a lot of predicted passes that are not seen.
>Is there some other software package that gives this information?

Not only QUICKSAT, but SKYMAP, SAT4.75, SEESAT, VIEWSAT do that !

But no program is better (or worse?) than its data. If you insert 
the expected average (intrinsic , i.e full phase, 1000 km) magnitude
into QUICKSATs quicksat.mag file, you get what you want.
SkyMap has its own file, which is based on averages (or Radar Cross
Section, when magnitude is unknown). SEESAT and VIEWSAT use the 
magnitude on the name line of the elsets, if present.
When missing, SKYMAP uses a selectable default, QUICKSAT prints it
as if it were 20.0, but picks them from two different standard 
magnitudes, depending on if it is a high USSPACECOM catalog number
(presumed bright) or a low one (presumed faint because magnitude unknown)

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