[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: AO40 Doppler



Howard:

What you did not do was give us the test conditions and where during
the orbit you found the "flaw" and where during the orbit you found
agreement.


It is likely that slightly different computational models will yield
different results near perigee when the satellite is moving really
quickly and differences in models would produce exaggerated differences
in Doppler predictions.

Can you re-run the tests and consider Doppler shifts near apogee and
near perigee so we can bound the ranges of the differences?

Bob

-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
Behalf Of Howard Long
Sent: Wednesday, May 29, 2002 4:43 AM
To: Paul Williamson
Cc: amsat-bb@AMSAT.Org; nlsa@nlsa.com
Subject: RE: [amsat-bb] AO40 Doppler


Hello Paul

I said

> >I also find that, for instance, the Doppler frequency predictions from
> >IT+InstantTune, Nova and Wisp+WispDDE are rarely in agreement, sometimes
out
> >to a couple of kHz.

Then Paul said...

> That's disturbing. If they all disagree, at most one of them can be right.

Mmm... well I just did a similar check to what I've done before, and I now
find everything pretty much in agreement. On AO-40 IT is within 20Hz of
Wisp+WispDDE. Nova 2.1r build 32 is 10Hz behind IT, so there is _not_ a
problem. My original comments now appear unfounded, so I apologise for
wasting your time!

Don't know what I'd being doing wrong all this time. Perhaps there was a
problem which has been corrected recently. Or operator error on my part... a
likely reason.

73 Howard G6LVB


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home