Long Baseline Underwater Positioning with Fusion of Saved and Current Measurements and Ambiguity Resolution. Part 2. Performance Evaluation

The results of the testing of the algorithm for determining the position of an autonomous underwater vehicle (AUV) using measurements of ranges to acoustic beacons and data from a water-speed log and heading indicator, proposed in Part 1, are considered. The essential features of the algorithm are that it starts running without a priori AUV coordinates and without a set of simultaneous measurements required to obtain an unambiguous navigation solution, recursive processing of current measurements and the measurements saved before the solution started in the same filter, taking into account the AUV position ambiguity and its resolution. The runtime of the proposed algorithm is compared with other possible solutions. The results of the simulation and field data postprocessing have made it possible to evaluate the time needed to obtain the first unambiguous solution and the accuracy of unambiguous solutions obtained with the use of the developed algorithm for different number and locations of acoustic beacons and AUV trajectories. Two types of desynchronization of the beacons and AUV clocks are considered: random and unknown; accordingly, either range or range-difference measurements are used. The solutions with and without taking into account the measurements saved before the algorithm started are compared.