A Design Method and Coordinate Determination Algorithm for Multi-element USBL Systems

摘要

This paper describes a design method and coordinate determination algorithm for multi-element ultra-short baseline (USBL) systems where the location of underwater objects is defined by measuring the distance to the object and by determination of the angular position of the object. The case of calculation of the Cartesian coordinates of the object in the carrier coordinate system is considered. The proposed design method and the algorithm are based on the utilization of multiple rotations of the basic (three-element) USBL receiving arrays around the horizontal and vertical axes associated with the carrier coordinate system. The proposed construction of multi-element receiving array allows to obtain different spatial orientations of the basic USBL arrays and to increase the consistency and reliability of object coordinate determination. In the article the case of a nine-element USBL system is considered. It is supposed that the spatial orientation of the receiving USBL array is controlled by the measurement of its pitch and roll angles in the carrier coordinate system. The coordinate determination algorithm for the proposed USBL system is designed and tested with the assumption that the USBL array can have significant inclination. The coordinate determination accuracy of the proposed (nine-element) USBL system is evaluated.