NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Position from altitude and azimuth.
From: Antoine Couëtte
Date: 2020 May 11, 02:19 -0700
From: Antoine Couëtte
Date: 2020 May 11, 02:19 -0700
Hello to all,
Parallax ...
Here, I incorrectly corrected Topocentric Height into Geocentric Height by HP0 (0.1453’) instead of HP (0.0835’) .
I then “artificiallly” increased Geocentric Height by such difference (0.0618’ or 3.7" which still remains within the 6" data accuracy specified here).
Fortunately in this example the extra-parallax effects in both Height and Azimuth due to WGS 84 vs. Spherical Earth are under 0.001’ .
Hence my WGS84 sanity check was immediately able to pick up this undue difference : Azimuth is fine, and we just need to decrease the height by 0.061’ .
Best Navigational Regards to all,
Antoine
