Need someone who is familiar with forest data analysis

Looking for expert in forest data analysis to help in a task Ground filter development: Implement a ground filtering and terrain normalization algorithm in R. For example, use the focal function in the raster package for filtering of local minima. Allow other points of the point cloud to also be ground returns if they do not exceed a certain angle or height above the closest local minima. Interpolate between ground returns to derive a DTM. A description of several bare-earth filter approaches can be found in Sithole & Vosselman (2004) in the Literature folder. ========================== Only need 2 algorithm