de Hoop, Maarten V.Nakamura, GenZhai, Jian2017-05-042017-05-042017de Hoop, Maarten V., Nakamura, Gen and Zhai, Jian. "Reconstruction of Lamé Moduli and Density at the Boundary Enabling Directional Elastic Wavefield Decomposition." <i>SIAM Journal on Applied Mathematics,</i> 77, no. 2 (2017) SIAM: 520-536. http://dx.doi.org/10.1137/16M1073406.https://hdl.handle.net/1911/94183We consider the inverse boundary value problem for the system of equations describing elastic waves in isotropic media on a bounded domain in $\mathbb{R}^3$ via a finite-time Laplace transform. The data are the dynamical Dirichlet-to-Neumann map. More precisely, using the full symbol of the transformed Dirichlet-to-Neumann map viewed as a semiclassical pseudodifferential operator, we give an explicit reconstruction of both Lamé parameters and the density, as well as their derivatives, at the boundary. We also show how this boundary reconstruction leads to a decomposition of incoming and outgoing waves.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1137/16M1073406