Analysis and Comparison of Array Gain and Directivity Index

Array gain and directivity index are two important indicators which are used to assess noise suppression performance of underwater array. In order to distinguish the physical meaning of the two indicators, first the related definition is expounded, then based on linear array model, the performance analysis and comparison about the two indicators is performed via Matlab numerical simulation. Meanwhile the effects of noise field characteristic, working frequency and array design on the two performance indicators are investigated in detail.