My fascination with ham radio and the International Space Station stepped up a notch today, as I was able to receive and decode my first image from the ISS.
Occasionally, the astronauts aboard the ISS turn on the SSTV (Slow Scan TV) equipment on their amateur radio station and beam signals from their vantage point back down to us amateurs on the ground.
After being tipped off via the ISS Fan Club website that SSTV was active, I calculated a suitable overhead path and connected the audio output of my 2 metre rig to the soundcard on my PC, and tuned in. The frequency in use for the downlink was 145.800MHz, and I set up a digital recorder to capture the received audio.
Without too much fiddling about, the image was received pretty well, with only a tiny bit of noise, and a fairly minor image attribute on the left. Here’s the received image:
The image was in the Martin M1 SSTV format, 320×256 pixels.
Video Showing ISS SSTV:
Here;s a short video showing how the image is received, using the free PC application MMSSTV
It was also possible to decode the image by holding an iPhone up to the rig’s speaker, using the SSTV app, as shown here:
For more on SSTV, see our article SSTV – The Basics