pTrack is a satellite tracking program for the Windows CE / Pocket PC palmtop computer. It was designed with simplicity in mind and does not support all the features found in larger satellite tracking packages.

Since I am responsible for the spacecraft operations at Surrey Satellite Technology Ltd I wrote pTrack primarily to warn me prior to acquisition of signal (AOS) from any of the spacecraft. Additionally, SSTL has customer groundstations worldwide and I needed to know when a satellite would pass over those groundstations.

Primary features of pTrack -:

I am using pTrack on a Casio E-105. Others are using it on other palmtop computers and it should run on any computers running Windows CE 2.11 or above. I haven’t tested it on Pocket PC (Windows CE 3.0). It has also been run on a handheld device under CE, however this will look rather strange!


Unfortunately, pTrack does not have an installation program (sorry!).

To install pTrack follow these steps -:

  1. Create a directory on you Palmtop \Program Files\pTrack
  2. Copy pTrack.EXE and World.MAP into this folder
  3. Download a NASA two line element (TLE) Keplerian element file, rename it KEPS.TXT, and put it in the same folder.
  4. Create a shortcut for pTrack.EXE into the start menu.
  5. Run pTrack
  6. When the program starts, Tap on the screen. A menu will appear – select "Station Setup".
  7. Enter your station information into the Station property sheet.
  8. On the "Satellites" sheet, enter the names of the satellites you wish to track, and the object numbers of those satellites (note that pTrack does not use the names of the satellites in the KEPS.TXT file – it will always list the satellites based on the name you enter in the setup). The object number is the first number on both lines in the TLEs.
  9. When you’ve entered all the satellites you are interested in, close the program and restart it. (There is no way from within the program to close it. To close the program, use the "System" applette in Control Panel.)
  10. When you restart, pTrack will take a while to calculate passes for all the satellites in the list.
  11. To update the keplerian elements, simply update KEPS.TXT. pTrack will periodically check if this file has changed and will automatically update itself.

Implementation notes and known bugs

At the moment, Palmtop computers and CE aren’t exactly the fastest computers around. While writing the program, I found it took an eternity to calculate the 24-hour pass list when you select that option. To get around this, pTrack calculates and maintains this list in the background. If you have your palmtop switched off for a long time, it can take a while to recalculate a full days passes. It is also possible for pTrack to get a little confused and possibly miss a pass if you turn your computer off and on repeatedly while it is generating this list – don’t worry, it will sort itself out.

I know that there is a bug with the alarm times during summer time.

pTrack is written using Visual C and uses the SGP4 orbital propagator for highest accuracy.


If you have comments on pTrack, please let me know by email – don’t expect a reply. Suggestions are also welcome, however remember that this software is designed as a lightweight satellite tracker. Additionally, until the processing power of palmtop computers increases it will not be possible to do too much more (I know – this probably won’t take very long!).


This software is copyright by Surrey Satellite Technology Ltd and pTrack is available for NON-COMMERCIAL use only. Commercial users, or users who intend to use pTrack as part of a larger ground segment, should contact the author at SSTL.

Two versions are currently available for different processors – the MIPS version, and the SH3 version.