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Introduction - Speed

One concern about programs such as WinOrbit is how fast they run - how frequently can the screen be updated, and what effect the program has on other programs running at the same time. Since speed is highly machine-dependent, I can only report what I have found on my personal system.

Test System Configuration

486DX33, 8 Meg physical RAM, WD 90C31 (Paradise) SVGA adaptor, 1024 x 768 x 256-color screen resolution.

Speed results

Basic orbital model, elliptical Geodetic model, tiled tracking maps, standard map colors, ground track and footprint display on.
1) Maps can be updated at about 5 per second (i.e. 5 maps take 1 second, 10 maps take 2 seconds).
2) Ephemeris calculations proceed at about 250-300 intervals/second (for example, 10 days of predictions at 2 minute intervals in 25 seconds). Time to actually print was not measured (depends on brand of printer!).

Optimizing speed

Choose a reasonable update interval (5-10 seconds is nice for LEO satellites).
Omit the ground track, solar illumination, footprint, and secondary satellite when not needed.
Use the Basic orbital model whenever possible.
Keep the number of maps and their size as small as possible. The latter (size) is especially important in systems without much memory, since every pixel is stored in memory and may have to be swapped frequently.
Use the standard map colors (for land and water). Changing these colors (but not the symbol colors) will slow the loading of the maps (but not the calculation or display).
The Globe display is VERY slow. I'm working on this. It will go a bit faster if you are not updating the maps frequently in real time (e.g. choose a 30 second interval, or change to Step mode). Also, the larger the Globe window, the longer it takes to draw.

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