Re: [amsat-bb] Oribt numbers and NORAD keps

[Jim White <jim@xxxxxxxxxxxxxxxxxxxxx>]

The last time this came up on amsat-bb there was discussion from Tom Clark 
and others indicating:
- There is no agreement among various agencies on how orbits should be counted
- NORAD just doesn't care about orbit numbers and doesn't use them for 
anything they do
- There is no assurance orbit numbers in their elements sets will stay 
consistent
- They aren't going to change they way they handle them

Based on that background I didn't bother to call my contacts in the 
analysis group at US Space Command regarding the AO-40 orbit number.

I'd suggest using orbit numbers is risky and if you want to be specific 
about when something takes place or is about to, use the UTC date/time.

Jim
jim@coloradosatellite.com

>Alan -
>
>I don't know if this the cause of the discrepancy or not, but different
>agencies use different orbit-counting methods.  Some make an increment
>at perigee whereas others us the ascending node.  Nova lets you choose
>which method you want in the Text Format window (accessed through the
>Individual View Configuration window).
>
>73,
>W9IP
>
>ne1h wrote:
> >
> > Did anyone else notice that the orbit numbers that Stacey mentioned
> > didn't match specifically with NOVA using the "516" keps for ao-40?
> >
> > Did the orbit error creap back into the keps, or maybe it was never
> > fixed that last time.
> >
> > Anyway, Nova showed 1 orbit higher for the same date/time as stacey
> > mentioned.
> >
> > Can someone else confirm and if so, can we get NORAD to fix it.  It
> > mades schedule changes tougher, when they are referenced by orbit #
> > and MA if the tracking software displays the wrong orbit :)
> >
> > Alan
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>
>--
>Michael R. Owen, Ph.D.                      Dept. of Geology
>Northern Lights Software Associates         St. Lawrence University
>http://www.nlsa.com                         mowen@stlawu.edu
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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