ROBUST MAXIMUM ENERGY ADAPTIVE MATCHED-FIELD PROCESSING

Adaptive array processing algorithms have achieved widespread use beca use they are very effective at rejecting unwanted signals (i.e., contr olling sidelobe levels) and in general have very good resolution (i.e. , have narrow mainlobes). However, many adaptive high-resolution array processing algorithms suffer a significant degradation in performance in the presence of environmental mismatch. This sensitivity to enviro nmental mismatch is of particular concern in problems such as acoustic array processing in the ocean where the array processor's knowledge o f the propagation characteristics of the ocean is usually imperfect. A maximum energy matched field processor is formulated which ''tunes'' the replica vector used by a minimum variance distortionless response (MVDR) matched field processor to adjust for fluctuations in the envir onment. The resulting processor has the same structure as the two-stag e MVDR processor interpretation of the adaptive minmax matched field p rocessor proposed previously. However, the criteria which the two proc essors use to ''tune'' replica vector differ. The result is that the M EMV processor achieves a level of performance superior to that of the adaptive minmax processor and dose to that of traditional adaptive pro cessors while limiting the sensitivity of the processor to environment al mismatch. An algorithm for implementing the processor is developed, and the performance of the processor is analyzed.