CoSaTrak - Computerised Satellite Tracking

by Wille Koorts and Greg Roberts

On Sun, 2 Apr 2000, Greg Roberts wrote:

"I did some tracking last night and had my best night so far - only lost one satellite when it went above 70 degrees elevation. Tracked another one, lost it near culmination but was able to pick it up as it decreased elevation. One satellite I had to rely on the program to track as it only gave a brief flash every minute or so - followed this satellite for 13 minutes. Another one was a brilliant flasher with a period of about 1 second."
.... several software and hardware upgrades later ....

On Tue, 16 May 2000, Greg Roberts wrote:

"What a fantastic night - I didn't expect much with the full Moon but it may as well not have been there. I got 16 satellites including several new ones. Your program worked without a hitch and is indeed a big advance on your previous version. I tried two "impossible tracks" - one at 75 degrees [culmination] and followed it all the way. Then I had one at 82 degrees and followed it with no trouble. I also had two satellites go through nice fields and one even did a nice flare in the field!"

If these two reports from my "beta tester", Greg Roberts don't wet your appetite for satellite tracking then I don't know what will. It was this enthusiastic kind of reporting that kept on encouraging me to improve the software while the continual achievement kept driving Greg to perfect his satellite tracking mount throughout the development of this joint project.

These pages describe amateur systems for automatically tracking artificial satellites which should easily be within the capabilities of most tinkerers.

A typical system consists of three major components;

An artists impression of a typical CaSaTrak system
A motorized Alt/Az telescope mount A simple Computer Interface A PC running CoSaTrak Parts of this may look very familiar to anyone who has already built Mel Bartel's system. The good news is that your system would be 100% compatible with the CoSaTrak software meaning that you can immediately start tracking satellites with your existing astronomical telescope. (Click here to see the limitations involved.)

Although all the software is being distributed as Freeware, any donations towards all the hours of staring at the code will be welcome. Please e-mail me for particulars or if you want to suggest improvements or be alerted when an update gets released.


  1. CoSaTrak - An overview of the control electronics and software - by Willie Koorts
  2. VideoTrak - An implementation using a low light video camera on an ex-MOONWATCH mount - by Greg Roberts
  3. VisuTrak - An implementation for doing visual satellite tracking on a home-made mount - by Willie Koorts
  4. Circuit Diagram of the control electronics
  5. Circuit Diagram for the CoSaTrak handset

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Last Update : 10 July 2000