Broadband geo-acoustic inversion from sparse data using genetic algorithms: results from the 1997 Geo-Acoustic Inversion Workshop

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, by simulation, the feasibility of reducing the number and complexity of acoustic measurements needed for geo-acoustic inversion. The entire bandwidth of the 1997 G-Acoustic Inversion Workshop data (25-500 Hz) was used to compensates for the lack of spatial information when a limited number of receivers is considered. 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 model

and observed pressure fields for the multi-layer case n.