Underwater acoustic technologies are a key component for exploring the behavior of marine fauna such as sea turtles, sharks, and seals. The animals are marked with acoustic devices (tags) that periodically emit signals encoding the device’s ID along with sensor data such as depth, temperature, or the dominant acceleration axis - data that is collected by a network of deployed receivers. In this work, we aim to optimize the locations of receivers for best tracking of acoustically tagged marine fauna, and provide a test case with tags suitable for megafauna tracking. The outcomes of such tracking allows the evaluation of the animals’ motion patterns, their hours of activity, and their social interactions. In particular, we focus on how to determine the receivers’ deployment positions to maximize the coverage area in which the tagged animals can be tracked. For example, an overly-condensed deployment may not allow accurate tracking, whereas a sparse one, may lead to a small coverage area due to too few detections. We formalize the question of where to best deploy the receivers as a non-convex constraint optimization problem that takes into account the local environment and the specifications of the tags, and offer a sub-optimal, low-complexity solution that can be applied to large testbeds. Numerical investigation for three stimulated sea environments shows that our proposed method is able to increase the localization coverage area by 30%, and results from a test case experiment demonstrate similar performance in a real sea environment. We share the implementation of our work to help researchers set up their own acoustic observatory.
Bibliographical noteFunding Information:
This work was supported in part by the MOST-BMBF German-Israeli Cooperation in Marine Sciences 2018-2020 (Grant # 3-16573), and by the MOST action for Agriculture, Environment, and Water for the year 2019 (Grant # 3-16728).
Copyright © 2022 Alexandri and Diamant.
- acoustic marine testbed
- acoustic tags
- acoustic telemetry
- anchor deployment
- underwater acoustic tracking
ASJC Scopus subject areas
- Global and Planetary Change
- Aquatic Science
- Water Science and Technology
- Environmental Science (miscellaneous)
- Ocean Engineering