I do gave the data as E-mailed to me each week from AMSAT via ARRL. I have an archive.
When I tried as you suggested, neither Orbitron nor predict showed the time I observed -- they both have it coming over at about 05:34Z. They appeared to use current keps.
Sent from my iPhone
On Apr 1, 2015, at 15:50, David G0MRF [email protected] wrote:
If I understand you correctly, you need to predict where the satellite was a couple of months ago.
To do that you need a set of keps from a date close to the one you are looking to predict. At present AO-73 shifts about 4 minutes over a period of 1 month, so you need to be within 1 week to get reasonable accuracy.
I believe Celestrak or possibly the AMSAT archive may have this data.....but it's not very often used.
-----Original Message----- From: Bryan Green [email protected] To: AMSAT-BB [email protected] Sent: Wed, 1 Apr 2015 22:24 Subject: [amsat-bb] A pass from the past
Long story short:
I have handwritten notes and a recording from a past AO-73 pass.
My notes are dated that the pass was from 05:18Z - 05:31Z on 2015-01-29.
My recording indicates that the start was at 05:19Z on 2015-01-29. (I have the clock on the MP3 device set to UTC).
I have a spreadsheet of every pass I've tracked since the beginning of the year, and I'm going back to update the AOS, Max, and LOS azimuths, since I didn't start recording those until February.
Here's what I did:
Fed the AMSAT TLE file from 2015-01-30 into Orbitron.
It predicts AO-73 AOS at 05:32Z, and LOS at 05:39Z
Got the old-school predict program, fed it the same file, and got exactly the same results.
How can I best simulate an orbit prediction from the past?
I have SatPC32 but I don't understand how to use it to get a pass prediction.
Thanks in advance for the help!
Bryan KL7CN/W6 _______________________________________________ Sent via [email protected] 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://amsat.org/mailman/listinfo/amsat-bb