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--- Geoffrey Kolbe  wrote:

> Very nice. I hope these aliens gave you a rubber dinghy so you can
> paddle to Pearl Harbour :-)

Hmmm... the Google Groups e-mail server must be running behind tonight,
because I haven't gotten the post that you're replying to yet.

But I can get the gist of it from the quoted text, and it's good to see
the different methods that people would use to solve the problem of "No
DR".

--
GregR



> To save reverse engineering the spread sheet, what were the
> analytical methods?
>
> Geoffrey Kolbe
>
> At 01:29 17/06/2008, you wrote:
> >You really know quite a lot.  If it's 0600GMT (approx their morning
> >twilight) and it's your evening twilight, you must be approx 12
> hours
> >different, or the other side of the world.  Plot the Ground Points
> of the
> >three stars as on the attached.  For latitudes up to the give 30 deg
> N,
> >the distortions aren't outrageous.  Draw the Zenith Distance Circles
> of
> >Position.  Spica is about the right length since it's North-South.
> Since
> >Vega-Pollux intersect somewhere not too far from north of Spica and
> are
> >mostly East-West, scale the lenghts on this plot by 1/cos(Lat).  So
> AP
> >could be somewhere near 25N, 157W.
> >
> >But no AP is needed it you're willing to do some math.  The attached
>
> >spread sheet shows two analytic methods (which, luckily give the
> same
> >answers).  It can be seen, the 3 intersection points are:  23-18.4N
> >157-17.5W, 23-18.4N 157-17.5W, and 23-18.3N 157-17.6W
> >
> >
> >>
> >
>
>
> >
>


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