NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: dip, dip short, distance off with buildings, etc.
From: Michael Bradley
Date: 2006 Jan 11, 19:16 -0000
From: Michael Bradley
Date: 2006 Jan 11, 19:16 -0000
Interesting physics, and enjoyable banter, however... My understanding is that terrestrial surveyors of old ( and RN surveyors of land features)got their local horizontal datum from a highly portable reference source, i.e. a leather bag of mercury. Exactly as the technique for finding the position of the back garden using a paint roller tray full of oil. In that type of situation, what's dip and near horizon refraction got to do with anything...why not do as the oldies did and avoid the problem...? Michael B 55 04 N 001 27 W
