Weather Satellite Chasing



Weather Satellites orbit the Earth, day and night, capturing images and beaming them back down to Earth. There are geostationary satellites, and polar obiting ones. My interest lies in receiving the APT (Automatic Picture Transmission) format data from the noaa series of satellites. These are Amplitude Modulated 2.4khz carrier on an FM signal with around 38khz deviation. As I don't have a dedicated WeatherSat receiver, I have been using my Icom IC-R20 instead, and I had, at one point, built a Quadrifilar Helix Antenna from Coax and Cardboard. The audio would be recorded or directly piped into a program called WXSat to be decoded. That being said, I haven't pursued this hobby in a long time.

When I started - this is all I could achieve: (Click the Image to hear what APT Transmissions sound like!)


That was achieved only with a dipole and trying to chase the satellite as it moved across the sky. While it wasn't really successful, I heard the first "pinging" sounds from the satellite and I saw some sort of imagery that looked like Earth. That intrigued me. I built a proper QFA antenna and placed it in the roof - and that's how I got these images (in no particular order):
A False Colour Image created with WXSat from the received image
noaa 15 Pass 1
noaa 15 Pass 2
noaa 15 Pass 3
noaa 17 Pass 1
noaa 17 Pass 2
noaa 18 Pass 1
noaa 18 Pass 2
noaa 18 Pass 3
noaa 18 Pass 4
noaa 19 Pass 1
noaa 19 Pass 2
noaa 19 Pass 3
noaa 19 Pass 4

As you can see, the results were better, but they still weren't as good as they could be. At this point, I was out of ideas. Besides trying to build or buy a proper weathersat radio, there wasn't much I could do to improve the situation. But what was interesting was, at this exact time, I was working with BlueSAT at UNSW, helping them to recable their antenna. They had a long Yagi Boom attached to motorized rotator equipment with a Yaesu groundstation transciever. To do the first test of their antenna - I decided to manually hand-track a Weather Satellite. The results below just blew me away (they were also posted on BlueSAT's front page - click for full size):

It was when I saw these pictures that I thought - "Hmm, my work is done." This is me on the day at the Groundstation: