%0 Conference Proceedings
%9 ACTI : Communications avec actes dans un congrès international
%A Xerri, W.
%A Saracco, G.
%A Ribodetti, Alessandra
%A Zomero, L.
%A Picon, P.
%T Estimating the depth of a buried polyethylene pipe by comparing propagation models
%D 2022
%L fdi:010086586
%G ENG
%P 7  multigr.
%U https://www.documentation.ird.fr/hor/fdi:010086586
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2023-08/010086586.pdf
%W Horizon (IRD)
%X In civil engineering, one of the crucial problems is the location of buried polyethylene pipes. For this type of material, electromagnetic waves are less suitable than acoustic waves (e.g. the necessity to introduce a metal cable into the pipeline making the method invasive, difficulty in differentiating between a gas pipe and a water pipe). By injecting an acoustic signature into the pipe it possible to estimate the passage of the plumb of the pipe, by considering the pipe as a secondary vibrating source. Our work aims to estimate the depth of these pipes by acoustic method and in a non-destructive way. For this we have developed a system to take real data measurements. From antenna processing methods (MUSIC algorithm called 'high resolution') that we have adapted to our problematic, we obtain an estimate of the parameters of interest. Promising results have been obtained on real data from a semi-controlled test area by considering a weakly heterogeneous semi-infinite medium with an average velocity. One of the main problems is that we have, a priori, no knowledge of the propagation medium. It can change drastically from one place of application to another. The challenge is the modeling of acoustic propagation, on a meter scale, in heterogeneous soil with vertical (trench). We present here different propagation simulations applied to our problem. A first modeling is to consider two slightly heterogeneous media, vertically stratified, each with an average speed of propagation, considering the ray theory (time modeling). The second will be based on finite difference propagation of the complete wave field (Operto et al., Geophysics, 2009) including the trench. The goal is to compare the two models on the scale of our problem and to study the accuracy of the depth estimate that we can reach (Cramer Rao bound).
%B Congrès Français d'Acoustique
%8 2022/04/11-15
%$ 120 ; 066 ; 126