Get Cooridnates of observer point, when using viewshed

[KlausGiesing]

When performing the viewshed analysis in web scene, the coordinates of observer point can not be retrieved.
These are necessary for the measures derived from the analysis, such as the placement of cameras or the flight altitude of the drone. Behavior similar to ArcGIS Earth would be desirable.

[MarkGambordella]

we are looking at about point across the City and need to create a field of view or view radius for each.  having difficulty setting that up.  only need a triangle or visibility from each point that has a distance of 200ft.  any help would be great.