Long-term autonomous hydrophones for large-scale hydroacoustic monitoring of the oceans

We have developed a set of long-term autonomous hydrophones dedicated to long-term monitoring of low-frequency sounds in the ocean (<;120Hz). Deploying arrays of such hydrophones (at least 4 instruments) proves a very efficient approach to monitor acoustic events of geological origin (earthquakes, icequakes), sea state or large baleen whales, over large and remote areas of the world ocean (up to 1000 km between instruments or more). Such approach takes advantage of the high sensitivity of hydrophones and of the long-range acoustic properties of the water column. Our instrument have been designed to be deployed for more than one year, continuously recording the ocean sounds at 240Hz with high dynamic 24-bit resolution.