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Re: NASA elements set 103

 STSPLUS always worked with any type of bird, LEO or HEO. What did _not_ work 
for HEO sats was the tabular pass prediction algoritm (it wouldn't work with 
mean motion smaller than 1.5 if I recall correctly). With this new version 
the limit has been decreased and pass prediction now works with satellites 
like AO40.

  As for accuracy, it will work well enough for hams, but it won't equal a 
program properly designed for HEO sats. That is because STSPLUS uses the SGP4 
orbital model in its calculations. This model is more suited for LEO orbits. 
For deep space orbits (birds like AO40's) one should use the SDP4 model and 
not SGP4.

  Anyway for our kind of activities I think it works good enough since we 
hams use relatively large beamwidth antennas, at least on AO40, so there 
shouldn't be any problems. STSPLUS is the program I use at my shack, its one 
of my favorites for its simplicity and efficiency.



On Thursday 05 July 2001 05:58, Thomas McDaniel wrote:
> Get the latest version of STSPLUS (0123) -- according to the info its
> supposed to work correctly with AO-40.  It is very close to Instant Track
> using these Keps.
> 73  Tom  n0ntx
> ----- Original Message -----
> From: "Frank Grossman (WB2BXO)" <flgrossman@earthlink.net>
> To: "Shlomo" <4x1as@netvision.net.il>; <amsat-bb@AMSAT.Org>
> Sent: Wednesday, July 04, 2001 15:45
> Subject: Re: [amsat-bb] NASA elements set 103
> > Will this data work with STSPLUS?  I read somewhere that STSPLUS won't
> work
> > with HEO birds since it was only designed for LEOs.  Would STSPLUS grant
> > good enough results--a few minutes in time or a few degrees in azimuth
> > and elevation off--for casual users or would the output be completely
> > wrong
> and
> > unusable.
> >
> > Thanks and 73!
> > Frank
> > wb2bxo@amsat.org
> >
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