Marine inertial measurement units: Communication, capabilities, and challenges

This paper describes the development of marine inertial measurement units (MIMUs) for the measurement of buoy motions. MIMUs are miniature, lowpower, low-cost devices that utilize off-the-shelf microelectromechanical system (MEMS) components to monitor motion. Two MIMU devices have been deployed off the coast of Ireland—using SmartBay’s test facilities and data infrastructure; these transmit buoy motion data to shore in real time. The recorded inertial data are used to develop algorithms that provide relevant information for marine applications, with the eventual aim of embedding these on the MIMU itself. Methods and results are presented of one such application—the measurement of significant wave height (Hs)—and are shown to be comparable to state-of-the-art solutions, at a fraction of the cost and power requirements. Additional applications and possible future developments of the work are also discussed.