From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: how to judge if an arc of a great circle crosses a quadrangle and calculate the positions of the intersects of  on a sphere surface
Date: Sun, 14 Mar 2010 12:52:06 +0000 (UTC)
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hi, guys. thanks for all your suggestions and discussions. I have looked throug and I'll read them carefully soon. All the points I'm considering are places in an area on the Earth surface with the longest distance up to ~5 degrees (~560km) and mean distance ~20km. Thus, only the smaller arc of a great circle is to be considered.

I have one other question: how can I take altitudes of the points into consideration? The difference of altitudes can be as large as 4km or even more, so altitude may be important.