I just love this story from Spaceweather.com about a guy hunting for live satellites using a radio. He’s looking for Zuma, a recently launched spy satellite, but then …
That is, until Scott Tilley started looking for Zuma. “When I saw the radio signature, I ran a program called STRF to identify it,” he says. Developed by Cees Bassa, a professional astronomer at the Netherlands Institute for Radio Astronomy, STRF treats Earth-orbiting satellites much like binary pulsars–deducing their orbital elements from the Doppler shifts of their radio signals. “The program immediately matched the orbit of the satellite I saw to IMAGE. It was that easy,” says Tilley.
And IMAGE was considered to be a dead satellite, having died in 2006 for unknown reasons. However, being solar powered, it’s come back to life. Read the whole story on Spaceweather, or go to Riddles In The Sky for more information from Tilley himself – I think.