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Hiker's Satellite Predictions

>>> "Bruce Prior" <n7rr@hotmail.com> 02/06/06 11:13 AM >>>
>... I will commence a ... trek on the Pacific Crest 
>National Scenic Trail (PCT)... I'm looking for a 
>"trail angel" to... provide me with regular 
>updates on APRS satellite passes and frequencies

This is a good idea, but failing that, it is also easy to
keep track of these satellites as long as you have
a watch on your wrist and a pencil and notepad.
I worked this up in great detail for each of the 
satellites and posted it on the AMSAT-BB several months
ago, but cannot find it now.

I made a table of these simple notes for each

1) The orbital period
2) For any given best pass on one day, how
much earlier or later the SAME best pass would
be each day.

With those two numbers you can estimate passes
well within the needs of APRS indefinately. 
For example.  PCsat1 has a pass exactly 30 minutes
earlier every day.  And then once a week or so,
you add 100 minutes to ratchet up a pass.

The idea being, as long as you monitor a pass
once every several days, and get a feel for the center
of the pass, you can predict for the next several 
days just using addition.

I sure wish I had kept a link to that little email...
where I had worked all this up...

For ISS it was something like 23 minutes earlier
each day (long term) and 27 minutes or 63 minutes
earlier each day...  (not the right numbers, but
you get the idea)...

de Wb4APR, Bob
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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