A Remote Sensor for Marine Mammal Localization
Acoustics, Biological/Ecological Effects: E. Malakshahi, J. McEachern, A. Forget, M. Watson, N. Doelle, C. Ferguson, S. Aljendi, J. Bousquet (2022/06/01)
The deployment of infrastructure in the ocean is often slowed due to the potential harm of
animals in the area. In the Bay of Fundy, the deployment of tidal farms have been explored for
several years, however there is a large population of harbour porpoises. In this work, a remote
passive localization system is proposed to track harbour porpoises using the sound emitted by
the animal. In comparison to active sonar systems, the proposed sensor does not send a pulse.
This reduces the potential noise pollution, as well as the energy consumption of the system.
In order to implement this real-time system, two core components are developed: the local
ization algorithm, as well as the communication link to return the information to the surface. A
complete design procedure is described in this report, including the analytical development, the
modelling and the testing of the system.
The proposed real-time algorithm relies on a compact hydrophone array that is designed to
detect bearing and range. The algorithm complexity is optimized to be programmed on a eld
programmable gate array (FPGA); the FPGA is used for parallel computing of the acoustic data.
The algorithm is tested using calibration data in realistic conditions, as well as with real
harbour porpoise echolocation samples that were collected in the Bay of Fundy in the Summer
2019.
The communication system as well as the hardware for the localization system are deployed
in the Aquatron. The analytical models, validated by the measurement results demonstrate the
great potential for magneto-inductive communication as a means to cross the air-water interface.
Additionally, these tests were used to con rm how the sensor array can be connected to the
processor to enable real-time localization.
Overall, the developed platform has great potential as a smart remote sensor node that can
be used to monitor the ocean in real-time.