Remote acoustic buoys provide crucial real-time underwater noise monitoring

Offshore wind farms have been continuously improving the technologies to address the ongoing public concern of underwater acoustic pollution during offshore works and its impact on marine mammals. Today, underwater noise monitoring (UNM) regulations, requiring them to measure and limit noise caused by building work, are present in most countries to protect the environment and more specifically aquatic life.

Acoustic buoys, basically anchored floats equipped with hydrophones and acoustic recorders, are used to evaluate the level of underwater noise on offshore wind farms. In 2021, Seatronics, a brand in Acteon’s data and robotics division, announced a global agreement with French manufacturer RTsys, to distribute their autonomous underwater vehicles (AUVs) and passive acoustic monitoring (PAM) sensors, including underwater recorders, data buoys and remote stations. The RTsys range of equipment is now available through Seatronics, an electronics and tooling brand in Acteon’s Data and Robotics division, global bases.

Since 2014, RTsys has been providing buoys equipped with acoustic recorders, which analyse data in real-time. Users on offshore wind farms, whether local regulators, developers or construction companies, have been able to measure real-time audio levels and carry out live monitoring when sound levels exceed regulation limits. The data sets are transmitted using 4G or iridium to a specific internet platform developed by RTsys. This algorithm is embedded in each underwater acoustic buoy. The web interface, which is an integral part of the system, is accessed at all times with a remote control, enabling multiple buoys synchronization and recording. Raw data can also be collected and stored for further analysis.