Data processing for high-resolution 3-D subbottom imaging system ‘‘kite.’’

Abstract

A high-resolution 3-D subbottom imaging system called ‘‘Kite’’ has been successfully tested in shallow ocean near Miami Beach in July 1991. Kite is a 24-channel hydrophone array towed laterally, i.e., the axis is perpendicular to the direction of the ship motion. An omni-directional piezoelectric source located at the center of the hydrophone array is excited with a half-wave at 4 kHz every second while towed at 1 m/s. Each hydrophone signal is recorded at 16 kHz in 16 bits using an IBM compatible computer and an A/D converter. The 3-D image processing is done by using a software for conventional multi-channel seismic reflection data. First, the 3-D image of compressional wave velocity is constructed. The density and shear wave velocity images are constructed assuming the normal consolidation stress condition [Yamamoto etal., Geophys. J. Int. 98, 173–182 (1989)]. The results show that Kite has a great advantage in that it produces in high-resolution 3-D subbottom images while its data can be handled in a conventional way. [Work supported by ONR.]