NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
An azimuth nomogram: what's under the hood?
From: Tony Oz
Date: 2018 Mar 12, 11:27 -0700
From: Tony Oz
Date: 2018 Mar 12, 11:27 -0700
Hello!
There is a nomogram to look-up an azimuth of a rising/setting celestial object. One enters it with observer's latitude (φ) and object's declination (δ) values, draws a line through these points - the third point is meant to show the azimuth according to the same name vs contrary name of (φ) and (δ). (If same name - on the inner scale, if contrary name - on the outer scale of the right wing of the parabola).
I wonder which formulas would let me to calculate the scales? Why a parabola was selected for the nomogram?
(I know that the parabola is one of the conical sections.)
Please comment.
Thank you in advance.
Regards,
Tony
