I have a group of observer points that I need horizon angles for (just East 0 deg and West 180 deg). I am thinking that I should be able to somehow extract these from the Viewshed, however the process is unclear. Does anyone know how this could be accomplished in viewshed or another application?
1 Answer
It is possible but the process is not exactly simple.
The first step is to use Skyline
tool to obtain skyline vertices (basically horizons). Then you need to convert vertices of skyline to points - tool Feature Vertices To Points
. Based on observation point and points from skyline you can calculate distance and horizontal angle using Generate Near Table
. From the result you can select your horizons - with angles 90 (East) a 270 (West) degrees (0 is North). With the knowledge of distance, Z value of skyline points and Z value + offset of the observer you can calculate the horizon angles.