Estimation method of parameters of near-field source based on rotating interferometer

Abstract

The invention discloses an estimation method of parameters of a near-field source based on a rotating interferometer, which mainly solves the problems that in the prior art, for the estimation method of parameters of a near-field source, the needed hardware system is complicated in structure and is high in algorithm complexity. The estimation method is realized by the following steps: 1) defining the array receiving data of the near-field source under the situation that the interferometer rotates; 2, comparing the array receiving data and completing digital integration so as to obtain a phase-difference sequence, and realizing the ambiguity resolution of parameters; 3) utilizing the difference of the maximum value and the minimum value of the phase-difference sequence to obtain the angle of pitch of the near-field source; 4) utilizing the array receiving data which is centrally symmetrical to form two correlation sequences; 5) utilizing the phase of the second correlation sequence to acquire the distance of the near-field source. According to the estimation method disclosed by the invention, the estimation of the three-dimensional parameters of the near-field source is realized by adopting the structure of the rotating interferometer. Compared with the method based on an interferometer with double long base lines, the estimation method disclosed by the invention has higher precision in parameter estimation and higher capability in the ambiguity resolution of parameters, and the estimation method can be used for positioning the target of the near-field source.

Description

technical field [0001] The invention belongs to the technical field of array signal processing, and in particular relates to a method for estimating near-field source parameters, which can be used for target positioning. Background technique [0002] The parameter estimation of spatial signal sources has always been one of the important research issues in the field of array signals. According to the distance between the signal source and the array, it can be divided into far-field signal source and near-field signal source. When the distance r>2D 2 / λ, the signal source is considered to be in the far field, and the signal arriving at the array is given in the form of a plane wave, and the location of the signal source is usually given by the direction of arrival. On the contrary, when the distance range is 0.62(D 3 / λ) 1 / 2 <r<2D 2 When / λ, the incoming wave signal can only be expressed in the form of spherical waves through the array, and the determination of t...

AI Technical Summary

Problems solved by technology

In order to avoid multi-dimensional search, Chen Jianfeng and others proposed a positioning method based on high-order cumulants in the paper "Joint Estimation Algorithm for Distance, Frequency and Angle of Arrival of Near-field Sources" (Acta Electronics, 2004, 32(5)), but due to the need to To construct a high-order cumulant matrix, the computational complexity is also very high

Wang Bo and others used the second-order cumulant in the paper "A Method for Estimating 3-D Parameters of Near-field Sources Based on Second-Order Statistics" (Journal of Electronics and Information Technology, 2006, 28(1)) to give the carrier frequency, distance and The three-dimensional estimation of the angle, the amount of calculation is significantly reduced, but there are still great difficulties in engineering applications and hardware implementation

In the paper "Analysis of Defuzzification Ability of Dual Baseline Interferometer" (Aerospace Electronic Countermeasures, 2013, 29(3)), Cao Fei et al. used the combination of double baselines to defuzzify, which can also be used for DOA estimation of near-field sources, and the direction finding speed is fast , but has high requirements for channel consistency, and the distance information needs to be known a priori

In the paper "Research and Implementation of Rotating Interferometer Defuzzification Method" (Acta Arrow and Guidance, 2010, 30(3)), Si Weijian et al. used the phase difference sequence measured by the rotating long baseline interferometer at different rotation angles to estimate DOA , although the complexity of the system is reduced, it is based on the far-field assumption of the signal source and does not consider the near-field situation, resulting in the inability to locate the signal source in the near-field environment

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