NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Henry's equal altitudes
From: Dave Walden
Date: 2009 Apr 26, 07:41 -0700
From: Dave Walden
Date: 2009 Apr 26, 07:41 -0700
From late 1800's thru early 1900's motion corrections were addressed by a number of texts. (See attached.) They began to be addressed when "fast", ocean steamers made such corrections more significant. Quoted: And: "The subject has been rather fully described and discussed by Raper, Bowditch, Lecky, and a host of others" What you are referring to is longitude by equal altitudes, generally using single altitudes on either side of noon, with no correction for motion of the observer (or changes in object declination) and no attempt to imrpove the fix by statistical means. Though "longitude by equal altitudes" is clearly the ancestor of the sorts of fixes we've been discussing, it is not the same thing. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---