NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Possible limitaion for distance measurement
From: George Huxtable
Date: 2009 Mar 11, 20:16 -0000
From: George Huxtable
Date: 2009 Mar 11, 20:16 -0000
Herbert Prinz wrote about the work of Bremiker. I've cope across that name before when years ago, on this list or its predecessor, we were discussing the finer points of lunar distances at some length. I had pointed out the subtle, but serious, effect of the changing lunar parallax on the apparent speed of the Moon against the stars, imagining that I might be the first to note this effect, which could halve the precision of lunar distance observations under certain circumstances. Someone coined the name "parallactic retardation" for that effect. However, I was not the first. Wolfgang, from his amazing index, discovered that it had all been worked out before, by a fellow called Bremiker. I haven't discovered any other publications, before or after Bremiker's, that have taken this matter seriously. If Herbert is discovering, in Bremiker's work, worst-case examples in which the precision of a lunar distance is only half of what you might otherwise expect, keep an open mind; Bremiker might be including the effects of parallactic retardation. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---