Wave Sensing in the Upper-Great Lakes Observing System

This paper reports the design and implementation of a low-cost inertial wave sensor (IWS) for installation on coastal environmental monitoring buoys. The University of Michigan’s Ocean Engineering Laboratory design integrates a Digi International Rabbit RCM3600 embedded controller with a Honeywell HMR3300 MEMS accelerometer to measure buoy accelerations and estimate directional and non-directional wave spectral information. This information is then output via standard RS-232 communications to the buoy data-logger for storage or real-time dissemination to data centers at the University of Michigan, the National Data Buoy Center, and others. Details of the electrical design and on-board processing, in addition to related research enabled by this device, are discussed. A comparison of observations with the Great Lakes Coastal Forecasting System predictions and future upgrades is also presented.