Means and Methods for Hydrological-Acoustic Support of High-Precision Long-Range Positioning of Underwater Objects

The article discusses the application of methods and means of general and satellite oceanology for the high-precision acoustic positioning of autonomous underwater vehicles (AUVs) at distances of hundreds of kilometers from control stations. The authors present the results of analyzing their long-term acoustic ranging studies, which revealed the specific features of low-frequency pulsed signal propagation in different hydrological-acoustic conditions in which underwater sound channels (USCs) of different origin form. Special attention is devoted to the possibility and efficiency of using long-term oceanological observation databases to form the spatiotemporal characteristics of USCs in areas for long-range navigation support to AUVs. Additionally, the authors consider the possibilities of sea surface observation by means of satellites to provide the unit that computes the AUV coordinates with data on the integral (effective) sound speed in the near-surface sound channel (NSSC), which forms in winter. The experimental testing results on applying oceanographic technical tools in the Sea of Japan have shown that they improve the accuracy and reliability of AUV navigation support at distances of hundreds of kilometers from coastal control stations. It is been shown that in summer-autumn and winter hydrological conditions, it is possible to determine the AUV coordinates with errors not exceeding hundredths of a percent at distances of hundreds of kilometers.