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Re: ex-meridian sights -

Subject: Re: ex-meridian sights -
From: Pierre Boucher (pboucher@XXX.XXX)
Date: Wed Feb 14 2001 - 09:33:26 EST

>Barrie - Your suggestion is in fact something that I have seen in a
>navigation examples book of mine. It is possible if the body is close to the
>observer's zenith around LAN to plot the circle of position (COP) from the
>altitude (since HO will be large and the COP radius small). Of course the
>altitude may be a bit too close to 90 degrees for a desirable observation.
>Then a LOP is taken just after (or could have been just before) this and the
>COP intersected with the LOP - assuming that the distance run between the
>two was insignificant. Perhaps someone has tried this.

One of the CPS Navigator Examination has a question related to this
practice. Each COP have to be plotted from the GP of the respective body
using there zenith distances. The two circle will intercept in two
places. The DR position is used to select the proper interception and to
determine the FIX.

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