Study On Both Detection Algorithm Based On Underwater Acoustic Array And Key Techniques Of Underwater Acoustic Array

High accuracy, high resolution and rapid localization method is an important partof the underwater acoustic array detection technology. In particular and complexacoustic environment, how to locate and track underwater targets accuracily andreal-time is an urgent problem which needs to be solved for the underwater detectionequipment. To satisfy actual application requirements in complex acousticenvironment, we made in-depth research about: underwater target localization theoryand method, array errors calibration method, synchronization sampling method forunderwater acoustic array system and underwater acoustic array system. The mainwork and contributions of the present thesis are follows:1. Aiming at the problem of classification and localization of the near-field andfar-mixed sources, an algorithm of classifying the two-dimensional mixed sourcesand estimating the range parameters is proposed using an alternate search method. Itachieves the classification of mixed sources and estimation of range parameters bymeans of low computational cost. Then, another algorithm of classifying thetwo-dimensional mixed sources and estimating the range parameters is proposedusing comparaing the size and number of roots. It can make good use of arrayaperture and has lower computational load than foregoing proposed algorithm. Finally,by extending the foregoing proposed algorithm, a three-dimensional mixed sourceslocalization algorithm is present to estimate the azimuth, elevation and rangeparameters.2. Considering that the conventional uniform linear array limits the angularresolution, a cross sparse array which is composed of two sparse linear array isstructured, and a three-dimensional near-field sources localization algorithm isproposed. It can extend the array aperture, avoid parameters match procedure, havelow computational cost, locate more signal sources simultaneously, and have betterangular resolution and parameters estimation accuracy.3. For the issue of single signal source localization and sensor-breakdown, using asparse linear array, a one-dimensional far-field single source DOA estimationalgorithm and its improved algorithm are developed, and the improved algorithm hasthe following advantages:1) requires less sensors to locate the target,2) has highangular resolution and parameters estimation accuracy,3) has low computational load.Then, two kinds of sparse orthogonal array structure are designed and combininggeometrical relationship and the foregoing proposed one-dimensional DOA estimation algorithm, a two-dimensional far-field single source localization algorithm is present.4. For two kinds of different array gain and phase errors model, two kinds of gainand phase errors active calibration algorithms with similar principle are proposed.They do not need to excute eigenvalue decomposition and have very lowcomputational cost. In addition, the parameters estimation accuracy of the proposedalgorithm is indenpend of the size of phase errors.5. Considering the trouble that the conventional underwater acoustic array has adissatisfied synchronization sampling accuracy, in this paper, two kinds ofhigh-performance synchronization sampling methods are proposed according to thecharacteristic of two kinds of different type signal transmission interface. The maincontent of these two kinds of methods include: analyze the mechanism of causing thesynchronization sampling error, set up a synchronization sampling model, propose theestimation/measurement/compensation methods of signal transmission delay and amethod of overcoming the signal phase jitter, and analyze the reason of affecting theresidual synchronization sampling error. Finally, the experiment results verify thesuperiority of the proposed algorithm.6. We simply describe the main modules and assembly process of the twounderwater acoustic arrays which are designed by our work team. We use one of thetwo underwater acoustic arrays to test the performance of both the proposed gain andphase active calibration algorithm in the sixth Chapter and single source DOAestimation in the fifth Chapter through the lake experiments, and the experimentresults verify the validity of the proposed algorithms.