Howard A. Chandler
George B. Smith
Naval Res. Lab., Code 7173, Stennis Space Center, MS 39529-5004
Sector-focusing (SF) has been shown to be effective at enhancing range-depth resolution while minimizing the instability caused by environmental mismatch. It has also been shown that a stable Bartlett type response could be obtained with SF using a small sector in range-depth space. This property is used to advantage when matched-field processing is used for source localization. By extending the sector focusing concept to include environmental parameter variation within the sector, high resolution may be selectively achieved. In this way greater resolution may be realized for a chosen set of search parameters by including in the sector, replicas derived from a set of ``neighboring'' environmental parameters. Conversely, by not including replicas derived from other ``known'' parameters, such as source range or depth, a broad Bartlett-like response may be obtained. Thus the estimate will simultaneously attain high resolution only in the selected search parameter while remaining insensitive to measurement errors in all other parameters, including errors in source location. Examples are presented for a simple parametrization scheme using the KRAKEN normal mode model to simulate a canonical shallow-water environment.