Research On Passive Acoustic Detection And Localization With Small Underwater Platform

The underwater operation platform has the characteristics of unmanned control andautonomous working, and also has the capabilities of autonomous detection and localizationfor surface ship and underwater target. The trend of unmanned battlefield requires longerrange, higher positioning accuracy and better hit efficiency of the underwater operationplatform.The theory and test research of the target detection and localization by underwater smallweapon platform were performed in this paper. The research background was described firstly.Then the development needs of the small weapon platform were analyzed. The localizationand tracking methods for underwater targets were reviewed and compared. The workingenvironment and the characteristics of the underwater platform were also analyzed.Detection systems working on the small underwater platform, thereby the formation andaperture of acoustic arrays are limited by the structure and size. So the working pattern andperformance of the acoustic detection system are limited too. Based on the analysis of theexisting small platform acoustic detection array, three kind of arrays were proposed whichwere suitable for the small platform. They were the plane three-sensor equilateral array, theplane three-sensor right angle array, and the cubic triangular pyramid array. The theoreticalpositioning formula was deduced. The impact factors of calculating accuracy were analyzed.The localization accuracy of surface target was studied by simulation. The positioningaccuracy and optimal positioning area of the three arrays were provided, which broads thedesign idea and provides a theoretical reference for underwater acoustic detection system onsmall platform.Small underwater platform detection includes the measurement of the position, range anddepth of underwater target. In order to solve the problem of underwater target positioning onthe stationary, single-point independent small underwater platform, the information ofmultipath propagation was fully utilized. The extraction of multipath delay was realized bythe cepstrum analysis. A novel underwater target positioning method was proposed whichcombined ultra short base-line direction finding and multipath delay estimation. Theeffectiveness and feasibility of the new method were verified by lake test data.The vector hydrophone technology was applied to underwater small platform detectionin this paper. A novel target detection method was proposed based on vector hydrophonepolarity signal processing. The calculating formula was deduced, the processing gain was analyzed, and it was validated by simulations. The design of ultra-low power consumptiontarget detection system was achieved by combining with the phase shift network. Thebottleneck of low power consumption and small-size of small underwater platform wasbroken. The validity and reliability were proved by lake test.Combining with the development requirement of underwater small weapon platform,three contributions were achieved with the system analysis. They were the arrangement ofdetection system, the theory analysis of signal processing method and technologyimplementation. A complete target detection scheme system was formed on the smallunderwater active attack weapon platform. The problem of the surface or underwater targetdetection and positioning on the small platform was resolved by the proposed positioningmethod. Simulations were performed to review the influence of the factors such as positioningaccuracy on the attack efficiency of the new active attack weapon platform. All the aboveworks are of great research significance and application value on developing the detectionsystem for new type mine weapons.