Low-cost inertial measurement of ocean waves

Although commercial wave buoys are the de facto standard for ocean wave measurement, and are highly accurate and reliable, their high cost of deployment and maintenance can render them impractical for many applications. This paper describes the measurement of simulated sea states in a wave tank using Tyndall Wireless Inertial Measurement Units (WIMUs). These inertial measurement units are miniature devices which combine a microcontroller, wireless communication capability, and solidstate MEMS sensors (accelerometer, gyroscope and magnetometer) with specialized algorithms for specific analytical tasks. Methods and results are described here for measurement of simulated sea states. These tests represent a range of wave heights and periods from which the performance of the system may be quantified. Wave height is measured with an accuracy of -3% ±5%, with period measured at 1% ±7%. These results are shown to be significantly better than those achieved using methods in the currently available literature.