Cover Page Prev Page Next Page About


If you'd like to try your hand at orbital prediction, but don't want to write all the user interface stuff, you can write a Windows "DLL" program. You must call the file "USERALGO.DLL", and put it in the startup directory (with Winorbit.exe) or somewhere on the DOS path. When the user algorithm is selected in Print Ephemeris, in the Map, or in the Satellite Window, your routine will be called to compute positions.
All parameters are passed to and from the program in a single "structure". See the example listing (USERALGO.C) for the format. Be advised that your code may be called multiple times with epochs that may not be sequential (for example when WinOrbit is looking for next AOS), or even with different satellites (for example when printing while tracking). So use care in storing intermediate results.
Optional. A sample program is included (this is the "Basic" algorithm, coded in C). This was compiled with Microsoft's Quick C for Windows. You'll need to refer to the Windows documentation for your particular C compiler to understand how a DLL works.

File Overview

Converted by Winhelp to Web