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Subject: Re: Timing Noon
From: Peter Fogg (ffive@XXX.XXX)
Date: Thu Apr 11 2002 - 17:54:11 EDT
Rod Deyo wrote:
> if you have time and an almanac, you don't need an accurate DR position or
> really any DR position at all. You can determine the circles of constant
> altitude for celestial bodies and find their best-fit intersection
> numerically.
>
> .
I understand that an LOP is, if extended at either end, a circle of equal
altitude. But how can you determine that LOP without reference to a DR? The
almanac gives a Geographical Point, so I guess you then calculate the circle by
reference to the measured (corrected) altitude? Have thought about using simple
trig. but the opposite side of that triangle is infinity? and the hypotenuse is
longer?
Will that explanation also cover 'their best-fit intersection numerically'?
Plotting certainly sounds easier. I find it very useful, when things seem to
get complicated, to take out my globe and work directly on it. Just need to be
a little careful as its an inflatable model!
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