Determination of integrated navigation system requirements for a landing craft using off the shelf hardware

There is a current need for landing craft/amphibious vehicle (AMPHIB) vehicles to support various naval missions. These missions require an accurate knowledge of position, velocity and attitude to support high-speed vehicle transit through a restricted passage, mapping, operations, environmental data gathering, object identification and location and monitoring functions. This paper presents the results of simulation studies that document the current state-of-the-art capabilities to provide accurate navigation information to support landing craft missions. The integrated navigation suite utilized in the study was composed of an inertial navigator, Doppler velocity log, GPS set and specialized processing and software incorporating a Kalman filter. This system incorporates equipment, which is state-of-art and available off-the-shelf. The paper documents the error models used in the simulation as well as assumptions made with associated rationale. The simulation studies were conducted for different missions when GPS was unavailable due to a jamming environment. Operations, without the benefit of GPS, commence within 25 nautical miles from shore and subsequent to system initialization. The effects of initial sensor and system calibration, vehicle speed, ship maneuvers, geophysical effects, availability of accurate position fixes and velocity update is provided.