| High frequency surface wave radar (HFSWR) operated in the HF band (3-30MHz), as the name suggests, employs the ground wave mode of radio wave propagation where the radar signal is guided by a good conducting surface such as the ocean surface to follow a path that essentially matches the earth's curvature. It is capable of all-weather remote sensing of large area ocean surface dynamics with relatively high precision. After more than40years' development, its capability of currents detection has been considered satisfying the requirements for routine marine observations while its wind and wave outputs have not reached the matched status.In the application of HFSWR, DOA performance is different with the different array pattern. Besides, the complicated environment of the antenna array will distort the array directional response, and the distortion will weaken the performance of various super-resolution methods, such as Multiple Signal Classification. Therefore, it is necessary to optimize and calibrate the array.This thesis analyzes and optimizes the radar array. The array errors were classified and the methods of error correction were studied. The thesis is divided into the following aspects:First, Based on the analysis of array error. Mathematical model of array signal process is founded to introduce the spatial spectrum estimation algorithm (e.g. MUSIC etc.).In order to comprehend the DOA (Direction of Arrival) estimate error, the impacts to radar direction finding from different kinds of array error are also introduced by simulation.Second, array optimization based on the array pattern and the array direction finding sensitivity. For the problem of performance degradation about direction estimation of multiple signal classification algorithm (MUSIC algorithm) considering the model error, the error of direction estimation of MUSIC algorithm is discussed. Through the Taylor expansion analysis, error sensitivity is defined, detailed analysis about the array sensitivity characteristics of the linear array and circular array are also presented. The analysis of theory is validated by the computer simulation. When the analysis of the sensitivity to direction is applied to the radar receiver array, the law of radar array sensitivity is drawn, which can be used in the optimization of radar array. The radar array is optimized based on the control of beam main disc and side-lobe and sensitivity. Given different weights, multi-objective array optimization is carried out, and the genetic optimize algorithm is used to achieve finding optimization.Third, Calibration of Array Errors. The method of array calibration is analyzed here, and AIS, as a typical method of active calibration, is discussed; In the area of passive calibration, this paper addresses a method based on sea echo, which is proved to be efficiency by simulation and applied in calibration of array error and mutual coupling error. For the problem of mutual coupling error calibration, two methods 'loop iteration' and 'characteristic decomposition'are discussed and compared by their performance. A loop iteration optimization method based on MUSIC subspace orthogonal characteristics is used here, as a passive calibration method solving the problem of error joint estimation, which is demonstrate by simulation.Fourth, Error Calibration Analysis for the Measured Data of HFSWR. Error calibration analysis is done for the measured data of HFSWR, taking the array of multi-frequency Radar for the11th Five-Year Plan and the array of distributed radar for the12th Five-Year Plan as examples respectively, this paper gives the analysis processing of array calibration for the HFSWR. Intelligent algorithm, combined with the passive calibration algorithm using sea echo, is proposed. The results for both the gain-phase error calibration and the mutual couplings error calibration show that the validity of algorithm of this paper.
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