That sounds super interesting. Is there a write up somewhere of the project?
Here's the report [1], written when I was a second year undergrad in 2010.
It's very basic. The species identification is based on matching contours of the spectrogram against some template contour. The multilateration was, embarrassingly, done by brute force by generating a dense 3D grid. At the time, I didn't have any knowledge of Kalman filters or anything that could have been helpful for actually tracking the bats.