Determination of pitch and roll angles from data buoys

Pitch and roll angles are crucial for determining directional wave information from data buoys. A gimbaled gyro sensor is typically used to provide the pitch and roll information. There are three alternatives using lighter, smaller, cheaper, and easier to handle sensors to determine this information: (1) deriving the angles by using magnetometers, (2) deriving the angles from angular rate sensors, and (3) direct pitch and roll angle outputs from a dedicated motion package. Two sets of data measured from two data buoys were used in this study. The results show the pitch and roll angles derived from angular rate sensors are better than those from the other two methods using the data from the gimbaled gyro sensor as a reference.