Re: camcorder tracking of Mir/STS

From: Robert Preston <rapr_at_med.pitt.edu>
Date: Tue, 6 Jun 1995 21:48:44 -0400

>Robert Preston <rapr_at_med.pitt.edu> wrote:
>> David, I don't know a formula but it's a trivial calculation from
>> the orbital inclination and RAAN figures in the TLE. Just subtract the
>> relevant angles, using your latitude. It's elementary solid geometry.

...and David calculated:
> declination=90-inclination degrees,
> R.A.=R.A.Ascending Node - 6 hours.
>Does that sound right?

Yes! And of course, your latitude is actually not part of that picture, as Bart
already mentioned in another post, and as you correctly deduced. I was
confusing the role of the latitude in determining the altitude of the pole
above the local horizon. Sorry for the confusion, but you figured it out
anyway.
(Actually, Walter Nissen gave ME the "trivial calculation" formulas a while
back: I worked through the geometry after-the-fact, so maybe it's only trivial
in retrospect, like many other things in life) ;-)

>On June 7.07 UT the pole would thus be near ra=7h 54m,dec=38.3deg,
>7.5 deg. northeast of the star Castor, 4 deg above my north horizon.
>Such low altitude will only allow rough alignment, if formula right.
>Comments welcomed.

Your calculation looks correct to me, 4 deg above your horizon at that time.

>I'll try the formula next time it's clear!

Let us know how it goes.

Robert Preston
Pittsburgh, PA
79deg 54' 41" W - 40deg 28' 11" N - 300 m/990ft
rapr_at_med.pitt.edu
Received on Tue Jun 06 1995 - 21:55:53 UTC

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