A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Jun 25, 08:14 -0700
What is given for the ISS on various web sights is the geographic position and altitude for any UT time. I got an ISS GP Lat 51.659° N ; Lon 4.069° W at an altitude of 225.78 nautical miles for 6/23/2014 16:15:29 UT. Then the Sun's Hc altitude and azimuth can be worked up using the GP as the assumed position ( Hc 37° 4.38' Az 261.2°). This should be enough information to get a position with a known Earth radius. The position error will be +/- 16' semi diameter of the Sun. There is another less accurate way to get a rough position and that is to measure the width of ISS in pixels ( 11px ) vs. known length ( 109 meters ) and then use the Sun as a yard stick ( 547px ) with a solar diameter of 31.47167' for the day of the image. This will give an approximate line of sight distance from the photographer to the ISS setting up a long distance piloting problem.
I have a hunch Frank has an easier way to do this though.