GPS and radar aided inertial navigation system for missile system applications

This paper provides an overview and preliminary performance assessment of an adapted version of the Raytheon Systems Company GPS Aided Inertial Navigation System (GAINS) for missile systems. In this particular application, a missile is fired off a ship to intercept an incoming target. The missile and the target are tracked by a ship-based radar system. The success of the mission depends on the missile navigation accuracy and the removal of alignment error between the missile and radar tracking system. The missile on-board inertial navigation system implements a Kalman filter to determine in-flight corrections to the navigation and radar alignment errors. The filter processes the GPS pseudo-range and delta range measurements as well as the ship-uplinked radar data. Descriptions of the GAINS navigation and alignment processing are discussed. Performance results obtained from time domain Monte Carlo simulation analysis are presented for a representative scenario. The results of the analysis show that improved navigation and radar alignment accuracy can be achieved by using both radar and GPS measurements rather than by using radar measurements only. This translates to improved design margin and reduced performance risk. On-going laboratory, field, and flight tests are also discussed.