Model-based correlators: interesting cases in underwater acoustics

S.M. Jesus
SiPLAB-FCT,  Universidade do Algarve
Faro, Portugal

Comments: download pdf file
Ref.:  in New Acoustics Selected Topics, Ed.  Ranz-Guerra and GAllego - Juarez, pp.139-152, CSIC, Madrid (España), ISBN 84-00-08111-0, 2003.

Abstract : Model-based correlators are in nowdays widely used in disciplines such ascommunications and underwater acoustics. These class of methods generally make strong assumptions on the data underlying physical model and develop dedicated processors that fully exploit the model structure. When the assumed model is a good description of the data, these methods achieve very high quality results since, in the mismatch free case, they are optimal for the single signal in white noise scenario. However, in presence of model mismatch this result is degraded. This paper presents a theoretical study that addresses the optimality of model-based correlators when compared with straight correlators in a model mismatch situation. It is shown that model-based correlators can suffer severe degradation in relatively mild mismatch scenarios and - more importantly - in that case model-based correlators are outperformed by simple signal correlators. The theory is supported by a few realistic examples drawn from underwater acoustics.