NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Latitude of Point Venus
From: Alexandre Eremenko
Date: 2007 Apr 30, 12:13 -0700
From: Alexandre Eremenko
Date: 2007 Apr 30, 12:13 -0700
In August-September 1777 (THIRD voyage) Cook and his astronomers tried to determine Latitude of Point Venus. 10 days of observations of Sun on August 29-Sept 16 gave S 17d28'.3 (sigma=0.2') (EACH of these observations was an average of I don't know how many. Same about next observations) 6 observations of stars North of Zenith gave S 17d28'.9 (sigma=0.3') 9 observations of stars South of Zenith gave S 17d29.9 (sigma=0.8') >From this they somehow derived the "total average" of S 17d29.1' And my best guess from Terraserver is S 17d29.8' (though one cannot be completely sure where their observatory was, it is plus minus 1/2 mile as I can judge. It is easier (for me) with longitude because the shore line goes N-S. So we see that averaging has limited possibilities. The main errors are systematic and their origin is unclear. This is completely confirmned by my own experience. Alex. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
