Distributed sub-array wave arrival direction estimation method

Abstract

The invention discloses a staggered base line angle measurement method based on a distributed sub-array. The problem that the angle is fuzzy in the distributed sub-array wave arrival direction estimation process is mainly solved. The method comprises the following implementation processes of: extracting a target signal from a radar echo; performing coarse angle measurement on a target signal by using a digital beam forming method; dividing the sub-array, equally dividing each sub-array into two novel sub-arrays, forming four novel sub-arrays, generating four base lines, and constructing a staggered relationship by two base lines selected from the four base lines; performing beam forming on the four sub-arrays, and calculating a phase difference observation value of the two base lines; calculating a value range of a fuzzy number by utilizing the constructed staggered relationship; and introducing a cost function, solving the fuzzy number by utilizing the minimum mean square error criterion, and solving the cost function value by utilizing the fuzzy number, so as to obtain a target wave arrival angle. The operation amount is reduced by adopting the processing method for constructing the difference of the two base lines, the calculation speed of the target arrival angle estimation is increased, and the method can be used for target identification.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, and relates to distributed radar angle measurement, specifically for distributed digital array radar, a multi-resolution angle measurement method based on distributed sub-array is proposed, which can be used for target positioning. Background technique [0002] Direction of Arrival (DOA) estimation is an important research direction in array signal processing, and has been widely used and studied in radar, communication, sonar and navigation and other fields. The DOA estimation performance of the array is limited by the array aperture. The larger the array aperture, the better the DOA estimation performance. Therefore, expanding the aperture is an important method to improve the angle measurement accuracy. The early microwave synthesis interferometric radar can effectively expand the aperture and improve the accuracy of angle estimation, but too small degrees of freedom limit the ...

AI Technical Summary

Problems solved by technology

This method provides a higher angle estimation accuracy than the dual-scale ESPRIT method, but it not only requires eigenvalue decomposition, but also requires a one-dimensional angle search for the MUSIC spectrum, which requires a large amount of computation and a large number of snapshots. Subspace fitting cannot be performed when the number of snapshots is small

[0008] Among the above methods, method 2 and method 3 can obtain high-precision DOA estimation, but require eigenvalue decomposition and angle search, and the amount of calculation is large

Although method 1 avoids eigenvalue decomposition, its array element utilization rate is relatively low, and the accuracy of angle measurement cannot meet the requirements of system design

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