An integrated GPS/INS navigation system for small AUVs using an asynchronous Kalman filter

A small AUV navigation system (SANS) is being developed at the Naval Postgraduate School. The SANS is an integrated GPS/INS navigation system composed of low-cost, small-size components. It is designed to demonstrate the feasibility of using a low-cost inertial measurement unit (IMU) to navigate between intermittent GPS fixes. The paper reports improvements to the SANS hardware, latest testing results after compensating heading-dependent derivations in the TCM-2 compass measurements, and development of an asynchronous Kalman filter for improved position estimation.