NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: H.O. 249, Vol. 1 as a guide for star selection for direct position computation?
From: David Fleming
Date: 2017 Oct 3, 11:19 -0700
From: David Fleming
Date: 2017 Oct 3, 11:19 -0700
Greg is right about selecting two bodies with azimuths 90 degrees apart.
We need TWO sights each of which determines ONE piece of information about our TWO dimensional position in space.
Those sights have to determine independent information about our position to be useful. If not at 90 degree azimuths then the sights are to some degree duplicative. They improve the uncertainty in their common direction but make the uncertainty in the perpendicular direction worse. This has nothing to do with how the analysis is carried out.
DaveF