The optimization of large linear arrays 1

Abstract

Methods are given for obtaining the optimum source distribution for a large, linear, sonar array. An ‘optimum’ distribution is defined here as one which minimizes the pattern beam width for a given side lobe level. Numerical results are given for various arrays having between 11 and 201 elements and a - 20 db side lobe level, and it is shown that these results can be used over a wide range of steering angles ${\mathit{\theta }}_c$ and element spacings $\mathit{d}\mathrm{/}\mathit{\lambda }$ . It is then shown that there are bounds on $\mathit{d}\mathrm{/}\mathit{\lambda }$ for a given ${\mathit{\theta }}_c$ and tables are given for these bounds. Finally, comparisons are made of the patterns due to an ‘optimum’, ‘modified optimum’ and uniform distribution for a 201 element broadside sonar array.