James A. Hawkins
Warren T. Wood
Douglas N. Lambert
Donald J. Walter
Naval Res. Lab., Stennis Space Center, MS 39529-5004
The degree to which surficial and subsurficial (5--10 m) sediment properties can be determined from their acoustic response to high-frequency (15--30 kHz) short-duration (0.1--0.3 ms) acoustic pulses has been investigated. The acoustic response of the sediment (echo) is assumed to be the convolution of the source pulse with the first several meters of the sediment represented in the time domain by a series of impulses for each reflecting surface. The impedance for each is then determined with a standard deconvolution algorithm. The problem is first approached using a synthetic earth model. The algorithm is next applied to field data collected with the Acoustic Sediment Classification System (ASCS). The results indicate the ability to resolve reflecting horizons and determine the impedance of the sediment surface and subsurface.