The Research Of Power Combing And DOA Estimation Of Distributed Array

Distributed array is a new type of the array system. With the flexible array layout and the unique construction of subarray, it has various reconfigurability, flexible maneuverability and admirable performance under setbacks and thus, being applied to the modern strategy radar system gradually. Besides, the sparse construction of distributed array can be equivalent to the large aperture antenna and make the sense to the spatial power combing. The paper has been published on distributed array is still less and most of them are focusing on angle measurement of some special radar array. Found on the situation, this thesis divides the distributed array into the emission array and the receiving array to research respectively and aiming at power combing efficiently of emission array and direction of arrival(DOA) estimation of receiving array with any manifold, proposes the new synthesize algorithm of distributed array and the new method of DOA estimation of distributed array with any manifold by comparing the differences between the traditional array and the distributed array. The main contents of this thesis are listed as follows:First of all, this thesis introduces the background and the relevant research dynamic, and discusses several traditional synthesize algorithms and DOA estimation methods simply with simulation analysis, which lay a foundation for later studies.Then, this thesis divides the power combing of distributed array into far-filed and near-filed power combing. Aiming at the problem of distributed array antenna synthesis without the knowledge of the expected pattern, a method based on off-grid with particle swarm optimization(PSO) is proposed in this paper. Based on the algorithm of PSO, this method carries on the Gradient searching again in the grid cell and finds the best position of array unit rapidly without the knowledge of the expected pattern and the full wave simulation result proves the validity of this method. Meanwhile, the on-off pattern of subarray by subarray synthesize cuts the channel costing of distributed array remarkably. Besides, this thesis also builds the model of the near-filed power combing of distributed array and implements the power combing of target effectively with the considering of the different polarization to different unit through the synthesize by micro genetic algorithm(MGA).At last, aiming at the problem of some algorithm such as dual-size ESPRIT fail to solve the DOA disambiguation of any manifold, an algorithm based on off-grid to solve the DOA disambiguation of any manifold is proposed in this paper. Based on the rough estimation, this algorithm compares the matrix of the current estimation and the data matrix of the receiving array actually and iterates the real direction of arrival wave rapidly and excellently. In addition, the result of analyzing the relationship between DOA disambiguation and grating lob indicates the location of DOA disambiguation agreeing with the location of grating lob and suppressing the DOA disambiguation by synthesizing the distributed array without grating lob effectively.