Broadband Geoacoustic Inversion from Sparse Data Using Genetic Algorithms

Abstract

Matched-field acoustic inversion techniques were investigated using data from sparsely populated vertical receiving arrays and a single receiver element. The purpose of considering sparse data sets is to investigate, under simulation, the feasibility of reducing the number and complexity of acoustic measurements needed for geoacoustic inversion. The entire bandwidth of the 1997 Geoacoustic Inversion Workshop provided data (25–500 Hz) was used which compensates for the lack of spatial information when a limited number of receivers is considered. The forward model PROSIM and inversion code SAGA were applied to benchmark cases: sd, wa, and n. The inversion results generally showed good agreement with the ground truth for full arrays, sparse arrays and single receiver elements. With a simple two-layer model, an effective sound speed profile in the bottom was determined which produced a good fit between the model and observed pressure fields for the multi-layer case n.