Estimation of dynamic alignment errors in shipboard firecontrol systems

A problem in fire control systems is the estimation of the relative alignment between remotely located target sensor and weapon coordinate frames. This paper describes and analyzes a shipboard system concept for estimating initial misalignments and compensating ships dynamic bending and flexure. The concept uses miniature strapdown inertial sensor assemblies at remote sensor/weapon stations to monitor instantaneous differences in rotational and translational motions. Equations are developed for Kalman filter estimation of alignment and flexure errors using incremental angular displacement and incremental velocity matching measurements. Optimal filter performance predictions are shown graphically for calm and rough sea conditions for both conventional and ring laser gyro inertial sensor assemblies.