Preliminary Lake Geneva echogram

Today, as I did laundry, I explored some of the acoustic data we collected Thursday on Lake Geneva during our shakedown cruise.

Here are 5 echograms from the five frequencies. An echogram shows depth on the y-axis and time on the x-axis. The boat was moving slowly as the data were collected. Understand the data are collected simultaneously with the different frequencies (or nearly so). I'm sorry the quality of the image is not good, but one can see fish schools near the lakebed. Also some solitary pelagic fish. In the 430 kHz echogram, I think we see zooplankton in the upper water column (see the red oval).  Acousticians collect ground truth samples with net tows (or other gears) to interpret their echograms. We begin that important work next week.