Re: HELP!

Alan Pickup (alan@wingar.demon.co.uk)
Mon, 3 May 1999 16:52:16 +0100

LWojack@aol.com writes

>Can anyone hear me?  My earlier posted question was apparently ignored!

Yes, Jonathan, you're coming through 5 and 9, and welcome to the list. I
should really have picked up on your earlier questions - your message was
sitting quietly in my pending tray waiting for those spare few minutes that
didn't come.

> I just signed on to the list.  But I have a question - is there any software 
> that will predict decays for my local area, and give times, azimuths, and 
> altitudes (so that I can see it)?  Or just use a standard sat. track program 
> and see if any of the decaying satellites will be visible?
>
> Also, have any observers ever watched a satellite explode?

For the first part, you must realise that you have to be extremely lucky to
catch a decay - a more realistic aim is to observe a decaying satellite during
its final days/hours of life. During this time, the satellite can appear
impressively brighter and faster across your sky since it is (or may be) so
much closer to you. Uncertainties in its time and position add to the
challenge.

For predictions, use a regular satellite prediction program such as Quicksat
plus up-to-date elsets such as those in my select.tle and dklist.tle files
(available from my WWW pages). Alternatively, you can employ the predicted
elsets I post here from time to time in my "Decay watch" notes - use the
predicted elset closest to your observing time. Or grab the elsets yourself by
logging into OIG at
    http://oig1.gsfc.nasa.gov/scripts/foxweb.dll/app01?

As for watching a satellite explode, I know of no visual observations other
than the disintegrations witnessed during re-entry events themselves.

>
>Another question: what web site is the best for getting TLE's/Orbital 
>Elements for most observable satellites?

I'm not sure there is a "best". If you havn't discovered the Visual Satellite
Observers Home Page at ...
    http://www2.satellite.eu.org/satintro.html
now is the time. This has links to several sources of elsets. One I favour is
Mike McCants' page at 
    http://www.fc.net/~mikem/
where Mike posts his alldat file, containing elsets for all but a few
classified objects, including lots of (probably) unobservable debris objects.
The "Molczan" file, available at several sites, has most observable satellites
while there are other lists which limit themselves to the brighter ones.


Alan
-- 
 Alan Pickup | COSPAR 2707:   55d53m48.7s N   3d11m51.2s W   156m asl
 Edinburgh   | Home:   alan@wingar.demon.co.uk    +44 (0)131 477 9144
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