Can a Near-Polar Prograde Satellite Appear to Be Retrograde?

From: David Oesper via Seesat-l <seesat-l_at_satobs.org>
Date: Mon, 19 Oct 2020 10:09:08 -0500
Back in April, I serendipitously recorded two near-polar satellites with orbital inclinations i between 82˚ and 88˚ that had an east-to-west component of motion instead of the expected west-to-east.  I am at latitude 43˚ N and the satellites were the following:

Cosmos 2039
1989-074B
i = 82.6˚
Observation date (UT): 20 Apr 2020 

ONEWEB-0022
2020-008E
i = 87.5˚
Observation date (UT): 21 Apr 2020

I suspect that the Earth’s rotation ~ 0.5 km/s may have something to do with these prograde satellites appearing to move slightly retrograde, but hope someone here can better explain the phenomenon or point us towards a reference.

Thanks much!

David Oesper
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Received on Mon Oct 19 2020 - 10:10:22 UTC

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