Space Angle Is Estimated That The Array Structure And Its Algorithm

The array -based high resolution direction-finding(DF) techniques are new techniques which are developed from the beamforming techniques ,the null pre-processing techniques and the spectrum estimation techniques. The main objective is to study all kinds of algorithms improving the performance of DF and the speed of operation. After 40 years' researching , the experts of all over the world in this field have proposed a number of algorithms and investigated their performances. Whatever algorithms you use, however, they must base on the special array configuration. The fundamental effects of the array configuration on the performance of DF remain unknown, so it is often overlooked that there are some theoretical lower limits on the DF performance which are imposed by the array geometry itself. It is no denying the fact that there are some effects of the array configuration on the performance of DF. This dissertation studies some problems related to the algorithms and the array configuration using the theory associated with the computer simulations as follows:(1). With the help of differential geometry, array configuration, array manifold, DF performance, DOA ambiguity and their relationships are studied. Influence of array geometries on the DF performance and ambiguity of array are analyzed. The expression characteristic of performance of array is derived. The meaningful conclusions are drawn. The construction methods of array geometries are discussed to meet the needs in different environment.(2). The overall algorithms of the resolution array direction-finding are studied .It is the most important in this dissertation for us to analyze the theoretical performance of DOA using MUSIC(Multiple Signal Classification) algorithm which is applied to estimate the independent signals and AP(Alteration Projection) algorithm which is applied to estimate the coherent signals associated with the special array configuration and give many quantitative analysis results by computer simulations. A series of important conclusions are drawn to provide the reference data in practical background.(3). The MDL(Minimum Description Length) estimation method of the number of sources impinging on the array is studied. We derive the MDL methods and demonstrate its validity to estimate the number of both the independent and coherent signals by computer simulations.