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Re: Sight reduction using a calculator's POL (arctan2) key
From: Lars Bergman
Date: 2018 Apr 3, 14:40 -0700
From: Lars Bergman
Date: 2018 Apr 3, 14:40 -0700
Robert wrote:
< r, A> = POL( tan dec cos lat - sin lat cos lha, -sin lha)
Hc = acos(r * cos dec)
Zn = A (add 360 if A is negative)
A trick to get rid of the 360° addition when A is negative is to change sign of the arguments in the POL function, and always add 180° to A, thus
< r, A> = POL( sin lat cos lha - tan dec cos lat, sin lha)
Hc = acos(r * cos dec)
Zn = 180° + A
Lars
