Noise Covariance Adaptation of Doppler Velocity Log Considering Vehicle’s Attitude

Doppler velocity Log (DVL) is a sensor offering velocity information. This paper analyzes the error characteristics of DVL measurements and proposes a noise covariance adaptation method by using the vehicle's attitude information. For the successful operation of various marine vehicles, proper navigation systems are required. Inertial navigation system (INS) is usually adopted as a main navigation system in many applications, but it has a characteristic of cumulatively increasing error with time. However, the errors can be suppressed by using another sensor such as DVL. The accuracy of DVL measurements is dependent to the distances to the sea floor along the transducer axes, and each distance is a function of the vehicle's attitude. The analysis is verified by computer simulations, and the result shows that the proposed method decreases the navigation errors.