Multibeam sub-bottom profiler: exploitation of experimental data

The use of a SBP 120 multibeam sub-bottom profiler (Kongsberg Maritime) during recent sea trials enabled us to acquire data in various sedimentary areas and to test the influence of different acquisition parameters. In the first section of this article, we describe the SBP 120 main features. Studying the oblique beams, we then show that the recorded signal mainly comes from coherent reflection. The use of large arrays provides a high source level and increases the directivity index at emission and reception, but we show that to image complex structures, it can be interesting to limit the arrays' length and to use a less directive device. In the last section, we show preliminary results of the exploitation of SBP 120 data to characterize the geological environment.