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Jeremy,
you're right, what I got is only an estimated position, which is meaningless
unless the 1900 ZT position is considered a DR position as it used to happen
before GPS.
I still have some navigation notes that my father took when he was an
Italian merchant marine deck officer. They are real life celnav problems and
if anyone is interested I would be glad to post some of them here.
Federico

-----Messaggio originale-----
Da: NavList@fer3.com [mailto:NavList@fer3.com] Per conto di
Anabasis
Inviato: venerd� 8 agosto 2008 22.26
A: NavList
Oggetto: [NavList /] Re: Exercise #14 Multi-Moon LOP's


Frederico,

Glad you worked them out.  I didn't bother posting a solution as
such.  Basically the given 1900 ZT position is a GPS fix, so that is
what we can assume to be the true position, and the celestial fix is
an error check of the GPS position (please no arguements on this point
as it is beyond the scope of this exercise.)

I plugged each moonline into my celestial program (SkyMate Pro) as
individual moon LOP's.  The computer then compared them and gave me a
fix of 14 deg 14.9' North; Longitude 142 deg 51.9' East.  This is a
1.7 nm error as compared to the 1900 fix via GPS.

The trouble with crossing an averaged LOP in this case with a course
line is that it does not give us a fix, but rather an "estimated
position."

This is an experiment I did to see if a fairly large number of sights
of the same body, shot in a relatively short period of time, could
give us a position of reasonable accuracy away from meridian transit.
As we can see, it is fairly accurate, certainly accurate enough for a
deep sea position.  The position probably would be more accurate if
the azimuth of the body was greater then 5.5 degrees, but that is why
I shot the moon, as the azimuth is changing rapidly, even away from
the time or meridian transit.

Jeremy


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