Joyce’s birds & a contest

As Joyce pointed out in her post the sounds of the multibeam and chirp system can be heard in most places on the ship and are now are constant companions.  I was able to record the sounds in a relatively quite passageway on the ship (using my cell phone believe it or not).

knudsen_em122_waveform

This image shows part of the waveform of the audio I recorded.  There are three pulses, the first and last are the Knudsen chirp and the middle pulse is the EM122 multibeam.

Below is the full audio, 3 chirps with the multibeam between chirps 1 and 2.

The multibeam can be tough to hear because it operates at a higher frequency than the chirp, so I slowed it down by 4x.

Here is the chirp, also slowed down 4x, just because it sounds cool.

And now for a challenge:  Take the mp3 with the chirp and multibeam pulses from above and figure out what frequencies the chirp and multibeam operate at.  The source is noisy so lets say that you need to be within 20% to get the answer right.  First one to post the correct answer wins a tee-shirt.

Robert Petersen

Fine print:  If you already know the answer then you can’t play.  You need to use the sound file to get the answer don’t look up the specs.  Also I’m in international waters so I don’t have to comply with any of those annoying rules that ‘man’ wants me to.