A Direction Finding Method Combining Sum-difference Beam and Beam Music

Abstract

The invention discloses a sum-difference beam and beam MUSIC combined direction-finding method. The method comprises the following steps: applying sum-difference beam angle-measurement to a single sub-array in a distributed array to obtain a rough estimation signal direction; performing static beam formation on the sub-array element signal to acquire an output signal; constructing a spatial spectrum function through the output signal, determining a valuation range according to a rough estimation result, and searching a spectral peak of the spatial spectrum function in the valuation range, thereby obtaining a signal estimation direction. The search range of the entire estimation angle utilizing the distributed array system is limited by utilizing the rough estimation result estimated by thesingle sub-array, so that an ambiguity angle caused by a grating lobe cannot occur in the range, an ambiguity resolving effect is reached, and the precise direction-finding of a target signal is realized.

Description

technical field [0001] The invention relates to the technical field of antennas, in particular to a direction finding method combining a sum-difference beam and a beam MUSIC. Background technique [0002] With the increasing number of space targets and the rapid development of space weapon countermeasures, higher requirements are put forward for the performance of phased array antennas. This requires narrowing the beam width of the array antenna, increasing the area of ​​the array aperture, increasing the number of antenna elements, and increasing the transmission power, so that the modern phased array develops in the direction of a giant array, and a distributed phased array appears accordingly. . [0003] The concept of distributed array first appeared in the 1970s, but it was not until the 1980s that people began to apply distributed arrays to the field of phased arrays. In the article "Distributed array radar" published in the 1980s, Heimiller et al. proposed to use mul...

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Problems solved by technology

[0005] However, for distributed arrays, due to the long distance and irregular arrangement between the arrays, although the MUSIC algorithm can still be used, the angle ambiguity problem will occur. The double-scale ESPRTT algorithm (VASYLYSHYN V I.Closed-formDOA estimation with multiscale unitary ESPRIT algorithm [C] Radar Conference, 2004.EURAD.First European.2004: 317-320) is the most commonly used defuzzification algorithm, but it is only suitable for rotationally symmetric array structures, literature (HE Z, ZHAO Z, NIE Z , etal.Method of solving ambiguity for sparse array via power estimation based on MUSIC algorithm[J].SignalProcessing, 2012, 92(2): 542546) Based on the MUSIC algorithm, an objective function is used to estimate the power of each spectral peak, Then use the obtained power as a reference to defuzzify, and the literature (Dang Xiaofang, Chen Boxiao, Yang Minglei. High-precision direction estimation of non-isomorphic distributed arrays based on root-RARE algorithm [J]. Systems Engineering and Electronic Technology, 2014, 36(6): 10271032) is based on the root-RARE algorithm for DOA defuzzification of non-homogeneous distributed arrays

[0006] Therefore, in the existing technology, the dual-scale ESPRIT algorithm is mostly used for distributed arrays to deal with the angular ambiguity caused by grating lobes. However, the ESPRIT algorithm has requirements on the array manifold and cannot be applied to distributed arrays arranged randomly. The MUSIC algorithm cannot be applied in practice due to the high computational complexity due to too many signals to be processed.

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