At 8:11 PM -0400 9/25/07, w3vvp wrote:

I am running Itrack. The visibility screen and map screen do not agree.Ao 51 was shown as visible for me at 00.00,the map screen showed it over Brazil.I have latest keps. What have I go set wrong?

Possible explanations:

1. You may have your own location set wrong, and InstantTrack thinks you're in or near Brazil. You can check this by looking for the little white X that InstantTrack draws on the map where it thinks you're located.

2. The visibility screen has relatively coarse time resolution. Each asterisk represents 15 minutes. In that much time, a low orbit satellite like AO-51 can easily cover the distance between your location in North America and Brazil. You may just be over-interpreting the visibility screen. You can investigate this by jumping to different fixed times on the map screen (hit T on the map screen) around the time in question.

3. It's possible you looked at one screen in local time and the other screen in UTC. Use the Z key to toggle between the two.

4. It's possible you have two satellites in the database named AO-51, with different elements, and you were looking at different satellites on the two screens. You can check this by looking at the satellite number displayed on the map screen and using that same satellite number to choose a satellite for the visibility screen.

If none of those suggestions leads you to a solution, please make a screen capture of each screen and email them to me along with your IT.ORB and IT.QTH files from the InstantTrack directory (usually C:\IT) and I will try to analyze your problem.

73 -Paul kb5mu@amsat.org InstantTrack HQ