Site Viewshed Analysis with DSM - Removing "false" visibility readings from trees and
I've been working on modeling a proposed building and running a visibility analysis to determine from what areas the building could potentially be seen using ArcGIS Desktop with 3D Analyst. Using a DSM raster derived from LiDAR (includes all points - ground, trees, buildings, etc.) as the base surface information so that above-ground sight obstructions are accounted for.
My process to find the areas that the new building could be seen from has been to set the proposed building roof corners and peaks as 3D points and use them as "observers" - if the roof corner can "see" an area, then the building can be seen from that area. I used the Visibility tool in the 3D Analyst toolbox and Model Builder to run through the observer points at the building roof (16 all together) to generate visibility rasters and then mosaic them together.
The issue is that using the DSM is a double-edged sword - using it to account for above-ground obstructions has also created speckled areas of "visibility" on treetops and building tops where the new building could be seen from if the observer's eyes were at that height. But obviously, an observer would not be standing on a rooftop or treetop, so these areas are erroneous. See image below (hillshade with red areas being visible from the proposed building site)
What's the best practice for dealing with removing these areas, besides manual cleanup? The LiDAR is not classified for vegetation and buildings, only ground and water, so using those LiDAR points as a mask to delete the erroneous areas would require some classification work.
أكثر...
I've been working on modeling a proposed building and running a visibility analysis to determine from what areas the building could potentially be seen using ArcGIS Desktop with 3D Analyst. Using a DSM raster derived from LiDAR (includes all points - ground, trees, buildings, etc.) as the base surface information so that above-ground sight obstructions are accounted for.
My process to find the areas that the new building could be seen from has been to set the proposed building roof corners and peaks as 3D points and use them as "observers" - if the roof corner can "see" an area, then the building can be seen from that area. I used the Visibility tool in the 3D Analyst toolbox and Model Builder to run through the observer points at the building roof (16 all together) to generate visibility rasters and then mosaic them together.
The issue is that using the DSM is a double-edged sword - using it to account for above-ground obstructions has also created speckled areas of "visibility" on treetops and building tops where the new building could be seen from if the observer's eyes were at that height. But obviously, an observer would not be standing on a rooftop or treetop, so these areas are erroneous. See image below (hillshade with red areas being visible from the proposed building site)
What's the best practice for dealing with removing these areas, besides manual cleanup? The LiDAR is not classified for vegetation and buildings, only ground and water, so using those LiDAR points as a mask to delete the erroneous areas would require some classification work.
أكثر...