Re: Mir seen at -0.8 degree?

Ron Lee (
Sat, 28 Dec 1996 22:08:30 -0700 (MST)

Where I observed my actual horizon may have been less than
0 degrees but I have nothing to measure it accurately.  I 
did use post-boost elements so that is not a problem.  Yes,
refraction does help.   If I had elements correct as of the
time of obs I might find that the elevation was not as low as
-0.8 degree but it was definitely low.

Ron Lee

>What has SKYMAP got to do with altitude? Altitude is observable
>directly. If an absurd result is attained in a computation then
>one usually assumes the computation (or the observation) is in
>error. Refraction will buy you, on the average, 0.5 degrees. Do
>you have a true or lower horizon? If you have a true horizon you
>cannot observe below an apparent altitude of zero.
>If timing is your criterion for altitude you pick a strange one,
>especially in light of the recent boost of Mir which should make
>it a bit late if your elements are old. Apparent altitude,
>especially near the horizon, is very easy to measure.