Research On Towed Line Array Shape Estimation Combining Acoustic With Non-acoustic Method

The distortion of the towed line array not only affects the performance of direction of arrival(DOA)estimation but also affects the performance of towed line array sonar detection.Due to the influence of the ship's maneuver and ocean currents,it is difficult for the towed line array to maintain its original shape in the water.The traditional straight line assumption has not met the demand,so it is extremely necessary to estimate the shape of towed line array.Most of the traditional towed line array shape estimation methods solely rely on acoustic or non-acoustic methods.This paper summarizes the existing methods,and analyzes the applicable conditions of acoustic methods and non-acoustic methods and their corresponding advantages and disadvantages.According to its advantages and disadvantages,a combination of acoustic and non-acoustic method is proposed to estimate the shape of towed line array.This paper introduces the shape estimation of single frequency and wideband signal using the eigenvector method in the acoustic sense and the attitude sensor in the nonacoustic sense under the known and unknown source directions.Also this paper quantifies the estimation error and proposes indicators of evaluating of the performance of shape estimation.In the sea experiment,the validity and feasibility of the combined acoustic with nonacoustic array shape estimation method are verified by comparing with the hypothetical straight array and also the performance of the method is analyzed in the known and unknown source direction,broadband and single frequency signal.Finally,a relatively simple array estimation method using towing ship's self-noise combined with array attitude sensor is also proposed.This paper has a good guiding role for the engineering application of towed line array shape estimation and has a high engineering application value.