Pole of a satellite orbit

From: Bart De Pontieu <BDP_at_MPE.MPE-GARCHING.MPG.DE>
Date: Tue, 6 Jun 1995 19:04:27 -0400

David Moore asked in seesat/455:
>I may piggyback on Celestron 8 telescope but I believe best solution is to
>tilt polar axis to pole of Mir's orbit (isn't this how Baker-Nunn tracking
>cameras used work i.e. tracking is mostly done in RA with this setup) and
>I haven't got formula for calculation where that is (ra/dec) given two
>line element set, lat/longitude, date/time.
>Formula must exist. Anyone got it?

Just subtract 90 degrees from the right ascension of the ascending node
(RAAN in the two line elements, the number right after the inclination) to
get the right ascension of the pole of the satellite's orbit.

The declination of the pole of the satellite's orbit is 90-inclination.

This is all independent of latitude and longitude of the observer.

The right ascension of the ascending node changes with time due to the
non-sphericity of the Earth, usually a few degrees per day. I don't have a
reference book at work now, but the formula can be found in any text about

And, oh, thanks very much for writing your introduction. It seems to be
a rarity these days ;-)

Received on Tue Jun 06 1995 - 18:37:20 UTC

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