Access to the point cloud from the B4 LiDAR scan permits us to
explore the effect of the method of preparation and resolution of
DEMs on their interpretability for tectonic geomorphology and
earthquake geology studies. The DEM represents topography as
measured by the heterogeneously distributed 3D laser returns as a
two dimensional grid of elevation values spaced at a constant
resolution. Computing the DEM from the scattered data is a
computationally intensive, but relatively straightforward task. Many
algorithms are available for these computations (e.g., El-Sheimy et al.,
2005). Where the resolution is greater than the typical shot spacing,
the DEM preparation method typically used is local binning (e.g.,
El-Sheimy et al., 2005; Kim et al., 2006) in which the value at a DEM
node is a simple function (e.g., maximum, minimum, mean, and
inverse distance weighted—IDW) of the points within a specified
search radius (r). Increasing the search radius ensures that points
will be found (otherwise a null is assigned at the grid node), but
the value will represent a broader area