Depends on th err inclination. Miss & SO-50 tend to repeat about every two week or so note that the passes tend to come earlier by about 15 minutes or so each day.

Rick Tejera K7TEJ Saguaro Astronomy Club www.SaguaroAstro.org Thunderbird Amateur Radio Club www.w7tbc.org

On May 10, 2016, at 21:14, B J va6bmj@gmail.com wrote:

On 5/11/16, Jason Rearick jbr13@md.metrocast.net wrote:

Yes, I have and use Gpredict, but don't know how far ahead to go to find when the birds come back around to about the same times as they did last month. I figure they are on a cycle that repeats every so many days, weeks,

or months.

<snip>

Keep in mind that Gpredict will only produce data for up to 50 orbits in the future.

Each day, I put the AOS times for the satellites I track into my computer's calendar program. Before I do that, I print out those 50 orbits as text files and import them into a database. I can then check the dates or specific times that a certain satellite will be visible.

A simple way would be to estimate the precession rate from that orbital data and do a back of the envelope calculation for when a bird will be in a favourable position.

Of course, one could always resort to looking up the necessary equations in an orbital mechanics text and do some number-crunching.

73s

Bernhard VA6BMJ @ DO33FL _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb