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Subject: Re: Still on LOP's
From: Peter Fogg (ffive@XXX.XXX)
Date: Wed May 22 2002 - 19:33:41 EDT
WSMurdoch@XXX.XXX wrote:
'Systematic errors expand some cocked hats and contract others.'
One error is built into our system, and that is that our LOPs are drawn
as straight lines, whereas they are really arcs, portions of circles.
The further the hat is from the intersection of the LOP and the azimuth
line the more pronounced this error will be.
Also, the further the fix position is from the DR the longer will be the
intercepts, and the less likely it is to be accurate.
The solution to both (and indeed generally helpful with regard to
errors?) is to redo the sight reduction process ( its as easy as
checking it carefully !) using the initial fix position as the new DR.
In theory this could be done indefinitely, but the Law of Diminishing
Returns means that you quickly (once or twice) exhaust its usefulness.
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