Researches On Localization And Target Property For Bistatic/multistatic Sonar

Because of the separable resource and receiver, Multistatic sonar have many special character in underwater target detect and localization. At present, the research of multistatic sonar has been taken an important thing. In this paper, an intensive study of the cruces technical of the multistatic sonar have been made from the point of multistatic geometry. The bistatic sonar localization and sound scattering of underwater target have been thoroughly studied. The bistatic scattering experiments have been carried through in tank. The main contributions of this dissertation are summarized as follows:(1) The sonar equations of bistatic sonar are developed from an energy point of view. The physics meaning of the parametric and the effects of the parametric on sonar equation have been studied. The research results show that the target strength and reverberation of bistatic sonar are different from those of monostatic sonar. Moreover, the bistatic operational range has been estimated for different frequency. The results show that the operational range of bistatic sonar is higher than that of monostatic sonar. The localization principle of bistatic sonar is given and the GDOP(Geometry Dilution Of Precision) which used in bistatic radar for describing the localization error has been cited in bistatic sonar.(2) Based on bistatic geometry, two simple localization methods TOL (Time-Only-Localization) and BOL (Bear-Only-Localization) have been proposed. Through numerical simulation, the accuracy of the methods has been intensively studied. The contour figures of localization errors are given. Moreover, the effects of the system parametric (such as baseline length, time measure error, sound velocity fluctuate and buoys errors) on localization accuracy are studied. The laws of the bistatic TOL and BOL localization algorithm are obtained.(3) In order to improve the localization accuracy of the sonar system, the redundancy information should be used. Based on the character of the bistatic sonar, four localization optimal algorithms are proposed. First, the weigh least square localization algorithm is given by improved the algorithm in bistatic radar. Throughnumerical simulation, the localization performance evaluation results are presented for various conditions. Second, the optimal linearity weigh data fusion algorithm is proposed by applied the theory of data fusion. The localization performance of the fusion system is enormously improved. The accuracy of the sonar is higher than the accuracy of the subsystem. Third, based on the non-linearity feature of the system, the LMF algorithm is given by using the non-linearity least square optimal method. The simulating results show that the accuracy of the algorithm approaches the Cramer-Rao-Bound. Finally, the radial based function network localization algorithm is present for bistatic sonar. The performance of the method is comparable with the LMF algorithm. The results show that the neural network method is a robust approach in bistatic localization.(4) Three multistatic sonar localization algorithm based on range information are proposed. Firstly, the TOL algorithm is given. The formulas are provided for both the position and the variance of the position estimates. Performance evaluation results are presented for various conditions. The optimal systems geometry is given. Secondly, by expanding the equation in a Taylor series about a reference point, the linearity least square algorithm is presented. The simulating results show that the accuracy of the method is closed to the Cramer-Rao-Bound. Thirdly, the neural network method is extended into multistatic sonar localization. The error figure of the method is described.(5) In order to investigate the localization, detection and estimate, the sound scattering mechanism of underwater target for multistatic sonar should be fully understood. The targets of simple shape are studied in the first place. The deformed cylinder method is given to research the sound scatter...