Ship motion measurement filter design

A procedure is presented for designing Kalman filters to measure linear and angular ship motion parameters using realistic models of the ship motion dynamics. The design is based on the state space modeling of ship motion dynamics. The designed filters exhibited significant accuracy improvement (order of magnitude) over filters which do not model ship dynamics. The sensitivity of the filter mechanization to mismodeling of dynamics is investigated. Bounding filter design techniques are used to minimize the effects of mismodeling. The particular measurement system investigated consisted of linear and angular accelerometers in a strapdown mode. The design techniques are also applicable to inertial instruments in a stable inertial platform mode.