Cued beamforming of passive arrays in the context of active-passive data fusion

Abstract

Active-passive data fusion seeks to exploit the complementary information measured simultaneously by active and passive sonar sensors: For instance, active sensors can provide good range estimates for a contact, while passive sensors can provide information on both the bearing of and the spectrum radiated by that contact. One aspect of this subject is the use of feedback, in which prior information is collected about the state of a contact in the data fusion framework, and then exploited to enhance the signal processing of data measured in that framework. Cued beamforming is one such method, in which a dense set of passive beams are steered toward regions of high contact probability, as determined by the result of the fusion of initial active and initial passive state estimates. The denser cued beams may then provide a refinement of the position estimate of the contact, as well as better isolation of its spectral signature. Comparisons of the effect of using cued beams are compared to the effect of using standard beams (those used without prior knowledge) on the state estimate of contacts in various scenarios using simulated data. [Work supported by ONR.]