Hi David,

thanks for this. How is this data comparable to:
http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html

or
http://www.celestrak.com/NORAD/elements/stations.txt

I tried to use
http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html
and
http://spaceflight.nasa.gov/realdat.../Post/JavaSSOP/orbit/SHUTTLE/SVPOST.html

to get a picture:

http://thomas-wehr.homeip.net/space/iss-position.php
http://thomas-wehr.homeip.net/space/earthview.php

but when you are watching these both you'll see small offsets especially when rendering closeups.

Ususally I use celestraks data an was quite happy in the past but nowadays I experience an offset between the ISS and the STS vector which gives estimated about 100km difference in groundtrack.

Any idea?