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It has for many years been a simple discipline of celestial navigation
to observe bodies abeam to check on course being made good and dead ahead
to check on speed over the ground - assuming chronometer accurate and a
second body on appropriate azimuth not available.

                                        Henry

On Mon, 6 Jun 2005 12:54:16 +0000 Yourname Here 
writes:
> Lu,
>
> I applaud your reasoning. There is a lot to be learned from your
> simple statements. It smacks of being an experienced offshore
> Naviguesser. I think you were describing that selecting bodies abeam
> is that the resultant LOP gives you a good basis for determening set
> and drift.
>
> Joel Jacobs
> --
> Visit our website
> http://www.landandseacollection.com
>
>
>
>
> -------------- Original message from Lu Abel :
> --------------
>
>
> > 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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