{'fraction_non_alphanumeric': 0.014103425117528543, 'fraction_numerical': 0.0, 'mean_word_length': 5.367521367521367, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
High Resolution Near-field Localization Method based on a Special Combination Linear Array

In order to achieve the high-precision positioning of underwater target from the close range, in this paper, a special combination of the linear array, which is composed of multiple mutually perpendicular sub-arrays, is proposed to overcome the problem of port and starboard ambiguity of a single linear array. And based on this special combination, an optimized MVDR near-field high resolution positioning method is proposed. Based on the matrix decomposition principle of MUSIC method, the covariance matrix of data received by the array is decomposed to obtain the signal subspace corresponding to the signal component and the noise subspace orthogonal to the signal component. Using the orthogonality of the two subspaces, the covariance matrix of the array output is optimized, and the optimized covariance matrix is used for MVDR focused beamforming to further improve the focusing and positioning performance of MVDR. Theoretical analysis and simulation results show that the combination of the special linear array can effectively overcome the fuzzy problem of target location. The positioning performance of the MUSIC near-field positioning method is higher than that of MVDR focused beamforming positioning method. The further processing of the covariance matrix can improve the performance of MVDR focused positioning method. The sea test further proves the effectiveness of the method.