A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Geoffrey Butt
Date: 2016 Dec 13, 12:03 -0800
In my experience of teaching Cel Nav in the UK, the "Point determinatif" defined by Posth P is known, rather prosaically, as the Intercept Terminal Point ('ITP' for short).
The "Computed Point" defined by Henry utilizes the resulting LOP to produce an 'improved' DR position - in that it satisifies the condition of lying on the LOP determined from one sight and is closest to the original DR position.
When aiming for a fix by 'Sight-Run-Sight' the Computed Point can be used as the starting point for plotting the intervening run - in that the other end of the plotted run provides both the point for plotting the transferred position line, but is also the best estimate available for the DR position for the second sight.