Method for estimating direction of arrival of radar low-elevation target

Abstract

The invention discloses a method for estimating the direction of arrival of a radar low-elevation target, which mainly solves the problem of large calculation of the estimation of the direction of arrival of the low-elevation target in the prior art. The method comprises the following steps of: 1, transmitting a group of narrowband phase reference pulse signals with bandwidth of not exceeding 1 percent of carrier frequency; 2, receiving radar echo data by using a uniform line array; 3, carrying out beam forming on the radar echo data, wherein the beam points 0 degree; 4, measuring a distance sampling unit and a Doppler channel in which a target is disposed; 5, re-accumulating the received radar echo data according to the obtained distance sampling unit and the Doppler channel; 6, constructing a matrix beam by using the re-accumulated data; and 7, solving the direction of arrival of the target for the constructed matrix beam by adopting a total least square method of generalized eigenvalue decomposition.

Description

technical field [0001] The invention belongs to the field of radar technology, in particular to a method for estimating the direction of arrival of a radar to a low-elevation angle target. Background technique [0002] Target location is an essential function of radar. When detecting a target at a low elevation angle, the radar beam hits the ground, so that the direct wave of the target and the multipath reflected wave reflected by the ground (sea) surface are superimposed in the main lobe of the antenna beam, and their Doppler frequency and echo delay are approximate Equal, this group of strongly correlated signals is received by the radar antenna at the same time, so that the radar angle estimation system cannot correctly estimate the direction of arrival of the target, which brings difficulties to target positioning. In order to solve this problem, the prior art has the following three methods: [0003] 1. Wu Xiangdong et al. proposed in the article "A low-elevation-ang...

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Problems solved by technology

[0006] The above method 1 and method 2 are both methods based on the data covariance matrix. Since the information available from the radar is not fully utilized, the requirements for the signal-to-noise ratio are relatively high, and they cannot be used for direction of arrival estimation in the case of a single sample number

[0007] Although method 3 has the advantages of low SNR threshold and fewer snapshots required, when there are many array elements and the search angle interval is small, the calculation amount of angle search will be very large, which makes the direction of arrival estimation system more difficult. Engineering implementation brings difficulties

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