Jim Kingdon wrote:
Is there an online source of ISS coordinates (2d - "point where the
ISS is currently overhead") or the TLE (Two Letter Epheremides)?

Uh, TLE is Two Line Elements (
http://en.wikipedia.org/wiki/Orbital_elements ).

Thanks Jim.
It was about 15 years since I last dabbled with TLEs (in my Mir
photographing days), hence the elements/ephemeris confusion

Did you look at http://web.austin.utexas.edu/edcannon/elements.htm ?
That's titled 'Sources of Satellite "Two-Line" Orbital Elements'
and links to some sites which are said to have such things.
I didn't dig far enough to see how closely it matches what you are
looking for...

My previous searches didn't come up with those two pages. Links from the
first one look like they will be useful for implementing the algorithm.

Checking the second one, most of the links are pages that I'd previous
found and ruled out (eg. need registration), were quoted in my original
post, or similar problems.
However I did find the following Amsat text page:

http://www.amsat.org/amsat/ftp/keps/current/nasa.all

This will be *much* easier to parse than the previous NASA html page
that I found. Also it has other satellites which will probably prove to
be a bonus.

Cheers,

Richard
--
Richard Marsden
Winwaed Software Technology LLC
http://www.winwaed.com
Tools and Add-ins for MapPoint - http://www.mapping-tools.com