Autonomous Recroders - HARPs and ARPs

       To monitor marine mammals and study ambient ocean noise over long periods, our group has develoepd autonomous acoustic recording devices in a number of different configurations for various marine environments. These devices are commonly referred to as HARPs (High-Frequency Acoustic Recording Packages) and the previous generation, less capable ARPs.


       The hydrophone is an underwater sensor that converts the pressure waves from underwater sounds into electrical voltages that get amplified.

Arrays - Towed and Fixed

       We utilize hydrophone arrays to acoustically monitor marine mammals in real time during small boat, ship and FLIP operations.  Hydrophone arrays provide the opportunity to combine visual and acoustical observations to elucidate correlations between marine mammal calls and variables such as species, gender and behavior.


       Sonobuoys are expendable underwater listening devices. The sonobuoy has 4 main components: a float, a radio transmitter, a saltwater battery, and a hydrophone.

Acoustic Tags

       We use acoustic recording tags to study the vocal and diving behavior of large cetaceans. The data collected has provided valuable information on the relationship between call production and behavior and on the swimming and feeding mechanics of baleen whales.

Software - Triton and LTSA plots

       Triton is a tool which can be used to evaluate acoustic data recorded by Autonomous Recorders such as ARPs and HARPs. These data are typically single channel, long duration (up to one year), continuous and scheduled duty-cycle time series. The time series data are often transformed to the spectral domain for evaluation as power spectra, spectrograms and Long Term Spectral Averages (LTSA).