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Charles Seitz wrote:

> May I suggest a noon sight fix might suffice for verification
> of the dead reckoning position required for a direction/intercept
> fix?  Might that fix actually be superior to a DR position that
> hasn't been updated during a period of prolonged cloud cover?

If I were running an "aged" DR, I think an LOP perpendicular to the DR
track would be the most useful way of getting a better estimated
position.  So a noon sight would be most useful on a north-south course.
  If I were running more E-W, I'd personally prefer a LOP sight from a
body (sun? moon?) directly ahead or astern.   In fact, this latter can
be generalized to any direction -- the best EP will likely be given by
an LOP perpendicular to the course and therefore from a body ahead or
astern.

Before the really smart people on this list jump on me -- I'll amend the
opening statement to wishing for an LOP perpendicular to my expected
direction of motion (ie, if I thought I might be being set by a current
I'd wish for an LOP that was perpendicular to the expected COG).  Even
more important, I might wish for a sight that gave me a LOP between me
and a dangerous area (shoals, coral atoll, ...) so I'd know how close to
it I was.

Lu Abel

   

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