A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2021 Apr 3, 06:47 -0700
Your mistake is on the very last lines: GMT = GMTpre + dT = 15:00:00 + 00:19:08 = 15:19:08. Then your GMT will be only 28s out, or 7' in longitude, a very good result. You do however have a large error (> 1.5°) in your sun altitude; this happens to cancel the 1.3' error in lunar distance. Thus the screen shot including altitudes shows a too good result.