trigonometric calculations

didereaux wrote:
"Ron Gibbs" wrote in message
. ..
Hi everyone:

I'm new to this group, and looking for assistance. I've been
struggling to get to grips with 3D spherical geometry, and I could
use some good references to useful books and/or online resources.

My problem is to transform azimuth/elevation coordinates to the
relative azimuth/elevation as measured from a tilted observation
plane. I have been trying to work through the compound angle
calculations from first principles, but it occurs to me that this
must have been done before. This is not student homework; I am a
professional optical engineer working on solar collection systems.

I now think I can do this, using 3D rotation matrices, and transforms
between spherical polar and cartesian coordinates.
Ron

Not the sole method, but look to Calculus. Specifically Translation of
Axis, usually calc II level. Not particularly demanding, but can be
tedious.

I recall making something of a project of this in sixth year high
school. It's possible in ordinary trig (I had no idea spherical trig
even existed at the time) but it takes a lot of concentration and
messing about with equations. I probably couldn't do it to save my life
today.

FoFP

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