Comparison of the two-way travel times of path lengths from the transmitter to the back wall, assuming the homogeneous interior of the HM based on the geometrical optics (top) and data-driven maximum peak identification (bottom) techniques. The topographies are shown for the 92-point system (left), and the 363-point system (middle). The two longest (red) and shortest (blue) paths for both the filtering methods are shown on the right.