Spectrum Analyzer     
   Audio Spectrum Analyzer App for the iPad     
   Audio Spectrum Analyzer App for the iPad     
The International Space Station is sending SSTV (Slow Scan TV) images on 145.8 MHz today through Friday. Here are two images I just copied from the 1938 UTC (2:48 PM EST) pass.
They were transmitted in PD120 mode, and copied using MultiMode Cocoa software (which I happened to write), on a netSDR receiver connected to a discone antenna (which is many years old, and missing several elements).
SSTV is a method of transmitting a picture using audio tones. It takes about two minutes to send an image. Hence the Slow part of Slow Scan TV.
What does SSTV sound like? Here’s a recording of the audio that produced the second image: http://radiohobbyist.org/blog/mypics/iss_sstv.mp3