Study On Adaptive Array Processing With Random And Time-varying Lineup

The technique of beam-forming, one most important part of array signal processing, has already been provided with integrated theory and method. In the field of underwater acoustic signal processing, beam-forming system is one kernel part of sonar and the foundation of that sonar possesses better tactics property. Moreover, the technique of adaptive signal processing, as one most important part of modern signal processing technique, possesses some particular advantages, such as simple algorithms, easily being carried out and no need for statistic and apriori information, thus it becomes one of preferred solutions to many practical problems of theory and project. So joining the advantages of both, that is, combining the technique of adaptive and beam-forming to implement adaptive beam-forming.Ordinary beam-forming system, is a scheduled beam-forming system, and may possess goodish capability of detection when it is in the isotropy noise environment. However, once there is near field interference, or background noise has some instability, the detection capability of sonar will be swiftly dropped, even will be bankrupted. Reversely, adaptive beam-forming system, through real-time studying, could reduce noise (include interference) and furthest enhance useful signal. Such as uniform linear array, when its lineup becomes aberration, adaptive beam-forming system could effectively estimate object's azimuth in some extent all the same. It is just the emphasis of this paper, that is, study on adaptive beam-forming when the array varies at any moment.After analyzing the fundamental of normal array processing, some familiar narrow-band and broad-band adaptive beam-forming algorithms has been introduced in this paper. And based on it, the paper makes analysis and simulation about adaptive beam-forming for sound pressure array. At the same time, the performance of these adaptive beam-forming under the lineup varying at any time also has been studied expressly. Due to vector hydrophone could concurrently measure information of sound pressure (scalar field) and velocity (vector field), and more information necessarily brings out better processing effect. So, in the end, the paper studies adaptive beam-forming for vector array, aiming at the form of(p + v)*v. The result of simulation displays that adaptive beam-forming of vector array not only conquers left and right ambiguity, but also improves the resolution of azimuth estimation.