[amsat-bb] Manual Estimating FASTRAC

[Robert Bruninga]

> Sent: Sunday, November 21, 2010 7:04 AM
> FASTRAC
> 1 90025U 0        10324.91941279 +.00047321 +00000-0 +66105-2
0 00053
> 2 90025 071.9688 138.3615 0022609 310.2956 049.6065
14.77203256000130

For those that do seat-of-the-pants tracking from your
mobile....

FASTRAC's orbit (the center of general pass times over your
area) generally moves about 18 minutes earlier every day.  But
where it is in that orbit is not an exact multiple of that.  

So for a good overhead pass on any given day, tomorrows similar
pass will actually be about 20 minutes LATER each day, but a
lower pass.  Then after two days,  jump back 80 minutes to get
back onto the peak pass.  So you can go +20, +20, then -80 then
+20, +20 then -80 etc..

I found this useful for portable operation on a long vacation
for estimateing tomorrows pass based on when I heard the packets
each day.

Bob, WB4APR