Regular readers of my blog will know that I’ve been working on building a satellite tracking system. The plan is to end up with a fully automatic Pan/Tilt positioning system with a high sensitivity video camera, millisecond accuracy video time overlay, and automated image processing of automated frames.

I’ve been busy the last two weeks converting code and waiting for deliveries to arrive.

I finally received the 50mm F1.4 lens I ordered off ebay. This lens is a lovely unit, especially for US$50. It’s nice and heavy with manual aperture and focus controls. A quick test on the light polluted skies of Auckland resulted in me being able to image stars of Magnitude 4, so it’s well within the limit for the project.

I’ve also received the GPS unit with all important 1-pulse-per-second output. This will form the backbone of my time overlay system which uses the MAX7456 video overlay chip.

I’ve also been very busy converting the C++ code by David.A.Vallado implementing the SGP4 and SDP4 formulae into Delphi/PAS files. So fair it’s looking promising, but I’m still to run the tests and confirm compliance with the C++ base code.

I’m also trying to optimize this code to run on an AVR micro controller. The code uses a lot of floating point maths and even at 20MHz it takes a good second to output a result.

I’m still not sure on exactly how my PC software will communicate with the device. It’ll either come down to a micro controller being sent the Two Line Element data and doing the SGP4/SDP4 calculation, or the PC software. If it’s the latter, there are plenty of issues to work through with regard to delays in the RS232 protocol and the best method to send real time linear commands to the micro controller.

Hopefully I’ll have more information and answers in the coming week.