NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Using "Clear & Analyze a Lunar" app
From: Bob Bossert
Date: 2025 Aug 22, 07:01 -0700
From: Bob Bossert
Date: 2025 Aug 22, 07:01 -0700
I've practiced taking Lunars in my backyard. Aug 17 UTC, I did a run of Venus-Moon. My best was .18' and my average was .6'
I'm looking at the Clear and Analyze Lunar Observation [Frank Reed's web app: https://clockwk.com/apps/clear/]. And trying to understand the algorithm for Error in lunar, Equivalent Error in Longitude, and Position Error. I'm sure the last 2 are based on derived Longitude.
I tried to calculate Longitude using the Law of Cosines formula. Substituting Ho for Hc, using the UTC derived from the LD to come up with different GHS, and using assumed Latitude from my DR (actually my GPS location). Doing the calculations, I get a much bigger difference in Longitude. Am I on the wrong path?
Thanks for your help.
