Quaternion-based Least-squares Method for Calibration of Transceiver Alignment for High-precision Underwater Positioning

This paper proposes an improved algorithm to estimate the angular misalignments of transceiver relative to attitude sensors for a high-precision USBL system. The procedure presented uses position measurements obtained with the un-calibrated system for a fixed seabed transponder. The angular misalignments of the USBL sensors are identified by an iterative least-squares estimator. The quaternion parameterization is adopted for the practical reason that the representation of quaternion for attitude is free from singularity problem. The proposed method estimates four elements of quaternion parameters directly from the observations without estimating the Direction-Cosine-Matrix (DCM). The results of simulation show the method presented in this paper is proved to improve the position precision effectively.