Amplitude tolerance analysis of curved sonar arrays

• Published in: OCEANS 2021: San Diego – Porto pp. 1 - 4
• Main Authors: Kirkebo, Jan Egil, Austeng, Andreas
• Format: Conference Proceeding
• Language: English
• Published: MTS 20.09.2021
• Subjects: amplitude tolerance; Analytical models; beamforming; curved arrays; Geometry; interval analysis; Oceans; Optimization; Planar arrays; sonar; Sonar applications; Tolerance analysis
• DOI: 10.23919/OCEANS44145.2021.9705923

In this paper tolerance analysis using interval arithmetic is applied to the problem of beampattern synthesis subject to amplitude excitation errors for curved sonar arrays with directive elements. In previous work, interval analysis has been proven as an analytical and computationally effective approach for finding robust upper and lower bounds of the beampattern for linear arrays with omni-directional elements constrained by some error tolerance. However, in sonar applications the arrays may have non-linear geometries (such as curved, circular or spherical), and the element directivity also has a significant impact on the beampattern. It is shown in this work that the framework of interval arithmetic for amplitude tolerance analysis for linear arrays with omni-directional elements can be extended to non-linear arrays with directive elements, and is also valid when the array is steered away from broadside. Thus, the upper and lower bounds of the beampattern subject to errors in the excitation amplitudes can be found analytically. Any realization of the element weights within the specified amplitude error bounds will then result in a beampattern that falls inside the analytically calculated error intervals. The method is demonstrated through simulations on a 10 element curved array with directive elements, with amplitude error tolerances in the range from 0% to 5% for the element weights.