Viewshed analysis in forested area

Discussion created by jordanawhite on Jul 2, 2013
Latest reply on Sep 2, 2013 by jeffrey.vanetten
I'm running viewshed analyses based on some countryside footpaths - I'm using a 5m DTM, but I want to incorporate more elements into this viewshed. I'll be converting shapefiles to rasters and assigning a z value so this can be added on top of the DTM.

However, the problem I'm envisaging is that when I add elements where viewshed points are present, this viewshed point will naturally be placed at the same level of the new DTM with added elements. I want to somehow have the viewshed points at the height of the original DTM. For example, if a footpath is going through a forest (which has been added as an element from the original shapefile) I don't want the viewshed point to be on top of this forest, but instead at the DTM "ground level". I understand that there will be no visibility for such instances but I would nonetheless like to keep such points.

I have the viewshed points as a point class and a line class. Perhaps by converting these into rasters then assigning this the DTM z value this can then replace other cells (i.e. where added forestry elements exist).

I feel there's probably a way of doing this in Raster Calculator, but I'm not sure exactly of the pathway to follow.

Any help would be greatly appreciated!