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P3D Orbit Patterns & Antenna Fixed-Elevation


I'm hoping that some of you satellite veterans can help answer a question I've
been considering for quite a while.  I'd very much like to set up an S-band
receiving capability for P3D, but I really can't afford antenna
elevation-control equipment.  While I don't profess any particular insight into
elliptical orbit mechanics, I do believe it's likely that for any given point on
earth, P3D's maximum elevation above the local horizon will follow some kind of
pattern.  For example, it might be that for the Chicago area P3D's maximum
elevation will fall between 20 and 30 degrees every tenth orbit during local
Spring and Fall (or something like that).  Perhaps the pattern will be much more
complicated, but still repeatable.  I don't know.  The point I'm leading to is
merely this; if there is a definite pattern, and the repetition rate of that
pattern is sufficiently high, it's then practical to fix the antenna elevation
and control only the azimuth.  Obviously, this kind of approach compromises
satellite access time, but does simplify station cost and complexity.

Have any of you run computer simulations of several hundred P3D passes over your
area and determined if a specific elevation pattern exists?  If so, I would
greatly appreciate it if you would publish the results of your study.  I'd
attempt such a study myself, but then I'd always question the validity of the
conclusions (Hi!). 

In any case, thanks and let's hope for successful P3D launch in 1999.

John P. Lutz N9JL
Gridsquare: EN51vm
Elevation ASL: 619 ft.

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