sat tracking for your local sats see when there next near you for free

look for heavens above


you an see how often comes near you amazing software

so also patterns on there to predict next pass for example make a note of date you start tracking then after a few cycles it should repeat some sort of sequence

easy ways to keep track and convert to a number (to make sure its in sync or whatever reason)

Example

If its every 2 days it would be this in binary 1 0
so remember 10 and your start date.


Another Example

if itsas often as ISS the binary could be 011011
So remember 11 0 11 Or 0 11 0

and your start date. but alot easy to draw up a month chart and compare to previous month to double check the results.