Az/El vs. Az/Alt

9 May 1997 13:22:31 -0800

Hi Bjorn,

You commented on my observation of Cosmos 1220 (#12054) which I observed to be
around 2nd magnitude.  I should say I was only ~mildly~ surprised by the
brightness.  The Molczan standard magnitude led to an underestimated apparent
magnitude of around 3.5.  I'd be surprised if this was due to a solar panel
effect, since the brightness varied smoothly as one would expect with range
and phase angle.  Perhaps the standard magnitude should be tweaked a little?

On a question of semantics, you asked:

"... On a complete sidetrack, which is (are?) the correct term pairs :

azimuth/altitude , azimuth/elevation, or azimuth/height ?

[and] which term should we use for what we measure in km, miles,
or nautical miles [above the] Earth's surface ?"

I've always preferred azimuth and elevation to describe ground-based angular
measurements (i.e. horizon coordinates).  I know some people use
azimuth/altitude, but for me the use of the word "altitude" is ambiguous in
some cases since it is also used to describe the physical distance between the
satellite and the ground.

So my 2 cents worth:

Angular position:  azimuth/elevation (angle, angle)

Physical position:  latitude/longitude/altitude (deg, deg, km)
                               X  /   Y  /  Z   (km, km, km)