Björn Gimle wrote: > Rob's SkyMap has had solar transit predictions since version 5.1 I experimented with it, after reverting a Windows Me laptop to a whiney old Windows 98 disk... I've subsequently learned that it's possible to run SkyMap on Windows XP, so maybe soon I can give it another try. Kevin Fetter used Rob's Earth.exe program, as well as STK 4, to check a solar transit photographed by Torsten Edelmann a while back: http://www.wonderplanets.de/iss-transit.html I analyzed the photo & determined that my centerline was about 250 meters northwest of the actual track. Kevin's results, using the nearest OIG TLE, were dead-on with Earth, and maybe 25 meters southeast with STK... however, I later thought that quite likely Kevin didn't factor in Torsten's elevation of 630 meters- since I forgot to tell him what the elevation was- which would have pushed the centerline about 125 meters to the southeast, for that transit. The ISS's solar panels are 73 meters wide, and the earth is about 8000 miles / 13000 km. in diameter, so at some point, reducing errors becomes difficult indeed. Obviously, predictions can be only as good as the TLE you base them on, and I don't have a good feel for what kind of TLE errors are typical for the ISS. ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sun Aug 31 2003 - 10:27:54 EDT