I am looking for the optimal location to place a radio repeater on a 25,000 acre preserve. Therefore, I need to determine a point with the largest viewshed of the property that is within a 1/4-mile buffer of a hiking trail or road.I have layers for the preserve boundaries, DEM, trails/roads, and a 1/4-mile buffer all laid out, but I am unsure how to proceed. I know there are viewshed and observer point tools, but I am not certain how to use them to my desired end.
are there any fire observation towers in the preserve?
There are not, unfortunately.
I was just trying to think of a shortcut for you to potentially find sites with optimal view. You could isolate areas of maximal elevation within your polygon buffer, however, that still doesn't guarantee that would be the optimal site. In any event, I doubt that a ground based point is going to be appropriate so perhaps you have other options (like a tower) that you are considering. This could broaden the candidate sites since there is going to be more that elevation that needs to be considered.
I would start by identifying ridgelines and sampling those pixels as potential observation points. You can get at ridgelines by finding pixels where flow accumulation = 0.
I'd start with the suggestion by Darren Wiens, and then consider using Modelbuilder (or Python) to iterate a Viewshed on each potential point (this may take several hours of run time), then compare the results.
Some thoughts/questions:
ArcGIS Help (10.2, 10.2.1, and 10.2.2)
Chris Donohue, GISP
Ok, these all seem like good suggestions. I need to try out the Viewshed tool a bit before I determine how to proceed. The DEM is clipped to our property boundaries, but I see now that the inholdings need to be represented regardless.
Iteractive visibility add-in http://www.arcgis.com/home/item.html?id=c6d74b84ab37454d9ae8cae6bbe4955f
Viewshed along a path (just add tower height to the extracted path elevation:
http://www.arcgis.com/home/item.html?id=3528bd72847c439f88190a137a1d0e67
I decided to use Flow Direction & Accumulation to ID ridgelines. I converted those pixels to a point shapefile, then split the shapefile into individual points using Dan Patterson's Split Layer By Attributes tool. I used Model Builder to iterate Viewshed on each point. Need some time to let it process, but I am hopeful.
If you have suggestions on what I should do differently, I'd still like to hear them. Thank you Dan Patterson, Darren Wiens, and Chris Donohue, GISP
please post your results...I would be interested in seeing the product.