Optical fiber combined array and grating lobe suppression method based on same

Abstract

The invention provides an optical fiber combined array and a grating lobe suppression method based on the same. The method includes the steps that 1, three sub-arrays of the optical combined array receive incident signals respectively, the optical fiber combined array comprises the three sub-arrays which are sequentially arrayed, all the sub-arrays are uniform and equal-interval linear arrays respectively, array element intervals inside all the sub-arrays are relatively prime, and the interval among the three sub-arrays is the half wave length of the received signals; 2, according to the incident signals received by all the sub-arrays, the relatively prime sub-arrays are used for conducting beam forming, and wave beam data output in each scanning direction is obtained; 3, by the utilization of the feature that the array element intervals of all the sub-arrays are relatively prime, wave beam domain information of the three sub-arrays is comprehensively processed, and a spatial spectrumafter grating lobe suppression and a target direction estimation result are obtained. Through the method, the reliability and accuracy of estimating a space target direction can be improved, and a higher resolution is obtained; compared with a traditional uniform area array, an equivalent aperture can be increased, the number of array elements can be decreased, and engineer practical value is high.

Description

technical field [0001] The invention relates to an optical fiber combination array. The application of the present invention also relates to a method for suppressing grating lobes based on an optical fiber composite array. Background technique [0002] Array signal processing uses the array to sample the signal in space and time, uses appropriate methods for calculation, processing and processing, and extracts useful information. Array signal processing has two basic tasks: one is beamforming, and the other is spatial spectrum estimation. Since the development of array signal processing theory, algorithms such as CBF, MVDR, MUSIC, ESPRIT, maximum likelihood method, and sparse reconstruction have appeared. Most of the above algorithms are based on a uniform array, and the internal array element spacing of a uniform array must be less than or equal to the half-wavelength of the incident signal, resulting in the array aperture being restricted by the number of array elements....

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Problems solved by technology

The object of the present invention is also to provide a grating lobe suppression method based on an optical fiber combined array that can solve the azimuth ambiguity problem caused by grating lobes when the fiber optic hydrophone array is used for azimuth estimation

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