Matched‐field processing with an L‐shaped array

Data was collected on a 64 element L‐shaped Array deployed in two at‐sea experiments: RDS‐1 off the coast of Halifax, Nova Scotia during late September of 1997, and KWIX‐98 off Key West, Florida in August of 1998. The L‐shaped array was deployed in a configuration with 32 elements in the horizontal and 32 elements in the vertical. Environmental variability during both experiments proved to be extreme at times due to weather and prevailing currents, making processing with so‐called ‘‘high‐resolution’’ and multi‐frequency matched‐field processing difficult. It was observed that fully coherent spatial processing using robust linear methods offered only marginal improvement over treating each leg of the array separately and combining the results in an incoherent processor. Possible explanations for these results are explored along with approaches aimed at improving the system performance. [Work supported by ONR.]