Abstract:

An analytical/experimental approach is presented to reconstruct the space-time pressure field in a plane and forward project the resultant space-time pressure field using tomographic and wave-vector frequency-domain methods. Transient pressure signals from an underwater ultrasonic planar transducer are first measured using a fiber-optic pressure sensor which is scanned across a plane at a fixed distance from the transducer. The resulting spatial line integrals in the plane are time-dependent signals that are first used to reconstruct the space-time pressure field in the plane via simply implemented tomographic methods. These signals are then used to forward project the space-time pressure field to arbitrary planes further from the transducer. Numerical results will be presented for transient signals to illustrate both the projection and the detection techniques. The results of the projected fields will be compared at various distances for synthetic signals and experimental data. [Work supported, in part, by the URI Ocean Technology Center and by ONR.]