Ultra high definition 3D tracking of biosonar of Amazon River dolphins and others mammals into the wild

Abstract

We designed and built a high capacity digital analog converter : JASON Qualilife DAQ [1] which is capable of sampling at 1 MHz on 5 channels simultaneously to assess cetacean biosonar and the source position and orientation relative to the array using time delay of arrivals of the biosonar acoustical signals. We used JASON with underwater portable arrays housing between 3 and 7 hydrophones (for more than 4 hydrophones we connected two cards sharing one common hydrophone). This has been used to monitor Physeter m. biosonar in near field, and Inia. g. in the Peruvian Amazon from 2014 to 2018. Results demonstrate the efficiency of this advanced low cost scientific instrumentation : it allows with only 4 hydrophones to track in 3D the precise movements of the I. g. dolphin, and to determine key behavioral features, like the velocity of its rostrum rotation, while following its highly defined biosonar emissions. This is the first, at our knowledge, that wild amazon dolphin biosonar is described inside its ecosystem. Perspectives on automatic low power trigger [2] for counting of the dolphins and extraction of individual acoustic invariant are given, as well as research avenues on biosonar of other species. [1] Gies et al, JASON Qualilife Daq, in DCLDE2018, smiot.univ-tln.fr,sabiod.org/bib [2] Fourniol et al., Low-Power Frequency Trigger for Environmental Internet of Things, in IEEE/ASME Mechatronic & Embedded Systems http://sabiod.org/bib, 2018 Samples and supp. material: http://sabiod.org/JASON.