A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Francis Upchurch
Date: 2017 Jan 6, 11:35 -0000
Just to add to my confusion, I tried your sight 1 with the Thompson abbreviated method and got a GMT of 8.17.29. (closer to your 8.23 approx time)
I’m not even sure if this method is appropriate for Venus lunars. I’m sure Frank would know. It mostly deals with parallax corrections for the moon. It also has a mysterious 3rd correction which Thompson kept secret, but I doubt whether it deals with Venus issues.
Anyway, hoping to hear the correct result to work out what I am doing wrong here.
Here are last night's results using Frank's calculator. I allowed the calculator to determine the altitudes of Venus and the Moon.
Error in Lunar -1.5'
Error in long 45.8' (approx 3 min time?)
Error in lunar -3.9'
Error in long 1° 57.6' (30 min time?)
Error in lunar 0.3'
Error in long 07.5' (approx 30 seconds time?)
I reworked sight 3, using my observed altitudes
Error in lunar -0.8'
Error in long 22.5' (approx 1.5 min time?)
Referring to the altitude observations my old school teacher would say Must try harder.