- pass prediction results are presented in four modes: text/tabular, two local sky simulation modes, «satellite over an Earth map» mode;

- able to syncronize the PC clock with NTP servers over the Internet;

- able to self-update the TLE files;

- very easy to use and handle (especially for beginners);

- it is principally made for visual observing (namely for the ISS with a magnitude up to -1).

The only problem is that it only allows a 30 day evaluation. After that it stops functioning

Note: This program is no longer under development.

The program offers four different views: 3D-Orthogonal View (the Earth is displayed as a sphere and the satellites orbit it); 2D-Equidistance Mercator View (the complete Earth's surface is displayed and the satellites are shown as icons); WDB-Equidistance Mercator View (it is possible to zoom into it and display just parts of the world's surface with geopolitical details); and Observer's view (useful if you want to know where you have to look to see a satellite). Each of this views offers a bunch of moving around features.

Notice that you can use this program not only for the GPS-satellites but for all other satellites as well, since it uses the standard NORAD two line elements files. We found it rather prone to crashing.

New in version 2.4 is the Weather dialog and the Internet dialog. Check them out. I did also some major internal restructuring on the graphics engine so that you can now use JPEG, GIF, EMF, WMF, TIFF, PCX, and BMP as Textures. The program needs Windows NT/95, the OpenGL DLL's and a color depth of at least 16 bit (65535 colors).

The program is written to be run as a background task while you are running other programs in your PC or doing odd jobs.

If you specify it, when a satellite is approaching, a sound alarm will be sent. The program will be restored on screen if it was reduced in the task bar and the name of the approaching satellite will blink yellow for a quick view.

As soon as a satellite is visible, the name of the satellite blinks green; an alarm is optionally sent and the program window is restored on screen if it was reduced in the task bar.

When a satellite disappears, its next visibility is immediately computed and monitoring restarts for this new visibility.

For each of the monitored satellites, SAT_EXPLORER provides a detailed description of the next or current visibility, minute by minute: elevation, azimuth, range, altitude, position, phase and Doppler shift. You can choose to monitor a further visibility if the next one is unusable because of a too low or to short visibility.

It can extract elements from practically any DOS Text file (UNIX files will be detected and a "fix" routine will ask for permission to convert to DOS format). You can drag an element file from the Desktop. You can open your web browser or email program or any text source of elements and cut and paste elements from those sources to the program.

Element Manager can manipulate elements in a number of ways. Selections to limit the number of active satellites based on the age, decay, inclination, eccentricity, mean motion, apogee, perigee, argument of perigee, right ascension of ascending node, International Launch Designation, common name, visual magnitude and radar cross section are possible

The program can make selections or exclusions by NORAD number. You can create multiple select files containing lists of satellites you are either interested in or wish to ignore.

This is the Windows version, there is also a DOS version available.