Re: Bright sat list / software

Willie Koorts (
Thu, 19 Dec 1996 10:16:40 +0200 (GMT+0200)

On Wed, 18 Dec 1996, Robert Sheaffer wrote:

> > show up when you make predictions using VISUAL.TLE.
> I was using it for a while. As I recall, it did not contain certain
> satellites like the "Lacrosse" series, which are quite bright. Consequently,
> I tried other sets. When I started using Molczan's elements set, all
> of the unidentifieds could be resolved (you sometimes had to fiddle
> with the program's brightness filter, as this "magnitudes" uncertainty is
> the Achilles' Heel of our hobby).
> Mostly, I'm using QUICKSAT and SKYMAP. Both will do this, but both
> rely on self-contained magnitudes files, and that of QUICKSAT is
> *strongly* biased to overstate the brightness of a satellite. Mike
> McCants is looking at other options for computing this.

Hi Robert and others

I also 'defaulted' to using QUICKSAT (and to some extent SKYMAP) for doing
all of my predictions.  I do some 'filtering' beforehand in the sense that
I extract a subset of the elements for just the satellites I want too look
at, from a (big) fresh element file (I prefer Molzan's since it gives the
sizes and standard magnitude in the header).  For this I wrote a little
program called EXTRACT (this should be in Neil Clifford's Oxford site and
will be on my own homepage as soon as I feel it's good enough to
distribute the URL). I then have a collection of text files (sometimes
edited from your mails) which contains the NORAD numbers and/or names (the
program accepts a mixture.  eg. if you just tell it 'Lacrosse' it would
extract all sats with the term Lacrosse in the name field) of the these
satellites I am interested in.  When I now do the predictions I set the
magnitude limit to something really faint (like 12) to make sure it gives
me all possible passes for these selected satellites. 

Once the predictions are done,  further filtering can be done depending 
on how bright the prediction program thinks the satellites will be.

As has been discussed already,  these text files needs to be kept up to 
date as satellites come and go.