Re: Warning for odd TLE

From: Michael R Thompson via Seesat-l <>
Date: Mon, 30 Mar 2020 19:34:10 +0000

What kind of error messages are you getting?

For what it's worth, I believe that that object may be hitting a limit of the propagator algorithm itself.  One of my implementations of SGP4 definitely fails, I'll see if I have anything for SDP4 coded up.  For something this high, it can definitely break some simplified general perturbations-based models.

From: Seesat-l <> on behalf of Jonathan McDowell via Seesat-l <>
Sent: Monday, March 30, 2020 3:02 PM
To: Leo Barhorst <>
Cc: Seesat-L <>
Subject: Re: Warning for odd TLE

I'll note that the mean motion (*not* mean anomaly) of 0.0347 is correct
for this object. It was 0.04 but
further lunisolar perturbations have  lowered the mean motion even further.
So it's worth making clear that the issue is a limitation of the software,
not an error in the TLEs.
 - Jonathan

On Mon, 30 Mar 2020 at 14:24, Leo Barhorst via Seesat-l <>

> Hello all,
> Last week I had problems reducing with Sattools the images I took.
> The cause of the problem was the TLE for NORAD 39459 that has a Mean
> Anomaly of 0.03 rev/day.
> After removing this TLE the program worked normally.
> This evening I saw in the recent downloaded catalog.tle that this TLE was
> still present with MA = 0.03
> So if you have problems this may be the cause.
> Greetings
> Leo Barhorst
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Received on Mon Mar 30 2020 - 14:34:59 UTC

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