Recent advances in the speed and capability of miniature computers have made possible a strapped-down mechanization for airborne inertial navigation systems. The implementation of this mechanization is critically dependent on the availability of suitable accelerometers and gyroscopes able to measure, and yet withstand, the effects of vehicle motion. The laser gyroscope is now considered a major contender for angular measurement in that it offers the possibility of a cheap, reliable instrument with the wide dynamic range required for strapped-down implementation.