4pUW8. Bottom scatter measurements and modeling from the California Continental Borderlands.

Session: Thursday Afternoon, December 5

Time: 3:13

Author: Charles W. Holland
Location: Planning Systems, Inc., McLean, VA 22102
Author: Peter Neumann
Location: Planning Systems, Inc., McLean, VA 22102
Author: Andy Rogers
Location: Planning Systems, Inc., McLean, VA 22102


Bottom scatter measurements were conducted in several littoral and deep-water regions using explosive charges (processes from 100 to 2000 Hz) and low-frequency (processed from 175 to 325 Hz) coherent sources. The measurements provide an opportunity to compare bottom scatter data using coherent and incoherent sources. The bottom scatter collected by coherent and incoherent sources appears to be identical within measurement uncertainties. This important result implies that survey measurement techniques (which use incoherent sources) may be employed for developing databases that support coherent systems. A variety of seafloor mechanisms controlled the scattering depending upon frequency, grazing angle, azimuth, and environment. However, modeling results indicate that the dominant scattering mechanisms arise from sub-bottom features and not the water-sediment interface. One important scattering mechanism appears to be a sub-bottom horizon. This kind of mechanism is generally not treated in current scattering models. A modeling approach is presented that captures the angular and frequency dependence of the sub-bottom horizon scattering. [Work supported by SPAWAR and ONR.]

ASA 132nd meeting - Hawaii, December 1996