Viewshed

[JustinBierschwale]

I am trying to come up with a process to create a raster that contains the viewable area from each individual cell throughout the raster. For example, when I click info on a cell I want the value to be some sort of area measurement (acres, square meters, square miles, etc). The area value is all surface area that particular cell can see added together.

My end goal is to reclassify that raster such that areas with extremely high viewable area values are in one category and the remaining areas are in another category. So, in mountainous terrain, the finished raster will primarily be ridge lines and other areas where topography changes drastically, but the areas within the terrain that have typical long range views but not panoramic will not be categorized the same. I hope that makes sense. I wouldn't say I'm a novice, but I am self taught so any help on that level would be appreciated. I'm working with ArcGIS Basic Desktop, Spatial Analyst and 3D Analyst.

[JohnWatt]

Hi Justin.  This is doable, but my approach has been 'computationally expensive'.  Involves running a viewshed as an iterated process (using model-builder iterator) on a point sitting on each cell (Raster to Point), then a table operation to turn Boolean 'visible' cell values into 'total visible cell count' for each cell.  Once you have a nice table with X,Y,Count as columns, you can easily map and symbolise, and translate cell count to viewable area.  

[JustinBierschwale]

Thank you for the feedback, John. Your suggestion is the only thing I can think of trying. I'm afraid it may take entirely too long to do the area I'd like to do. Seems like such an important way to view the earth's topography that someone would have come up with either a method to reduce the expense, or USGS et al would perform it and create a public base layer. I really appreciate the feedback and the visual.