How do you remove the forest canopy from a Phodar DEM to get bare earth?

[Anonymous User]

I'm trying to create a bare earth DEM from Phodar data to create a detailed contour layer. Is there a way to smooth or remove the high points of the canopy?

[IanMurray]

Are the points classified at all?

[XanderBakker]

I saw a nice presentation on Improved Vegetation Management with PhoDAR by Dave Twichell, BBaldwin-esristaff  and David Shear which you can find here: http://www.esri.com/events/transmission-summit/~/media/A36CC282BBCA42ABB06F527A648DF5E6 

In this presentation there is a comparison between PhoDAR and LiDAR:

Since PhoDAR does not penetrate canopy you will not have any information on the bare earth elevation for areas with dense vegetation. Although in the same presentation the vegetation was classified and one could extract those areas that have no vegetation from your DSM, but you will have to fill up those wholes that are left. In case of large vegetation areas, it will be very difficult to derive a good DEM/DTM from your PhoDAR data.