Abstract
A 3.5 kilohertz subbottom profiler was calibrated such that digitized signals from reflections can be used to quantitatively describe the acoustic response of the seafloor. Two methods were used to calibrate the system, both methods require measuring the seafloor reflectivity and relating it to the signal received from the seafloor reflection. One method uses the relative energies of the primary seafloor reflection and the first multiple to measure the seafloor reflectivity and relates this back to the primary. The other method uses the relative energies of the transmitted signal and the seafloor reflection as received by a suspended hydrophone and relates the measured seafloor reflectivity to the reflection received by the subbottom profiler. Both calibration methods produce a single term which contains the unknown parameters of the subbottom profiler, all of which are assumed to be constant. The two methods yielded consistent results. A calibrated system can be used to estimate geoacoustic parameters of the seafloor by measuring the seafloor reflectivity and relating parameters of interest through regression relations developed by various researchers. Some examples of estimated geoacoustic parameters are given. Profiles that were recorded were quantitatively analyzed to ascertain the effects of topography and layering.
Ebel, Martin (1993). The estimation of geotechnical properties of marine sediments from their acoustic reflectivity. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -E15.