The alignment of ship launched missile IN systems

The author outlines the requirements for on-board inertial navigation systems in the next generation of tactical missiles. The significance of alignment accuracy in the performance of such missile systems is discussed, drawing attention to the physical processes which introduce alignment error in a ship launched missile. Two different techniques which may be used to alleviate the problems of alignment inaccuracy are discussed. The first method involves the use of shipboard inertial measurements to carry out an alignment prior to launch. Such methods are strongly dependent on ship motion. The second method involves tracking the missile with the ship´s radar and the use of the radar measurements to aid the missile navigation system during flight. The author outlines the integration of the different measurements, the algorithms needed to implement each scheme and concludes with a comparison of the relative merits of shipboard and in-flight alignment