Here is a interesting signal picked up by the Allen array recently:

Watch and listen to baudline process this usual modulated signal collected at 1424.79 MHz for the setiQuest project at the Allen Telescope Array (ATA). It has a strange sine frequency modulated carrier with bursts of data. An unusual 605 baud pulse modulation is being used. The odd startup frequency chirp (drift) looks RC and is likely caused by something in the transmission line charging up. This signal is a mystery and we do not know what the source is.

In this movie the mystery modulated signal is played twice. First at a faster playback speed and then at half speed. Note how the audio clarity is increased when the low and high pass filters are enabled.

Three instances of the baudline signal analyzer are used in this listen demonstration. One baudline to play and adjust the playback speed and filters. A second baudline is recording and displaying a Fourier transform. The third baudline is recording and displaying a correlation transform with different color aperture settings and sample rate. The FM sine modulation, the data bursts, and the pulse coding make this an extremely interesting signal to watch and listen to. The "baud'ing" is clearly visible in both Fourier and correlation domains at the slower playback speed later in the movie. Next step, demodulation.