ASA 125th Meeting Ottawa 1993 May

5aUW13. Optimal array configurations for a Bartlett beamformer in an Arctic environment.

R. D. Huston

Defence Res. Establ. Pacific, FMO Victoria, BC V0S 1B0, Canada

Optimal or near-optimal array configurations for a vertical array in a shallow-water Arctic environment were determined using a Bartlett matched-field beamformer. A normal mode model was employed to calculate the acoustic field for a range-independent waveguide, and a simulated annealing (SA) algorithm was implimented to solve the combinitorial aspect of this problem. The cost function was designed to minimize sidelobes and the mainlobe width in the ambiguity surface, with the objective of optimizing the localization accuracy of the Bartlett beamformer. Exhaustive searches, which are possible for arrays with up to five hydrophones, confirmed the accuracy of array configurations from the SA method. An analysis of the range dependence of these solutions compares the localization accuracy from optimal and conventional uniform arrays for 8, 16, and 32 hydrophones at source ranges between 10 and 40 km.