APT WX Satellite RX

There’s a great piece of software (with a freeware distribution) for both LINUX and Windows at present going by the name of WXtoImg. It uses the power of modern day soundcards to do the grunt work of decoding the received audio signal and turning it into a picture that means something.

Although any off the shelf RX is capable of receiving the APT downlink around 137MHz, in order to get truely respectable results a more specialised FM receiver with a wider than average IF bandwidth is required.

I’m currently using a EBay sourced TimeStep receiver originally intended to do the decode on board and send data to a Windows PC. However, an audio output has been sourced from the board and the decoding half is now redundant, the received audio instead being fed directly into the soundcard of the server.

A home-made turnstile antenna has been designed and constructed and pressed into service. Initially it is only mounted 1m above the level of the back lawn but a more lofty perch is planned over a sunny weekend. This has not stopped the receiver delivering some excellent results even with a very clutter horizon at present. The intention being to upload the latest decoded images to the Weather Station area of the site.

A sample image decode is shown below. This was taken from NOAA 17 on the morning of 3rd June 2009.

Comments are closed.