A synthetic travel time dataset is provided without any information about the structures, we are going to apply delay-time and travel time tomography methods using the slope-curvature features to find out what the structures look like. Solve a first-arrival travel time tomography problem for layered earth model with sharp layer interfaces. The curvature-slope descriptors derived from the travel time curve will allow us to produce a clustering process using structural similarity. Each segment entry will time travel to reverse identification method with constraints on the eigenvalues with model regularization applied.