I have a point data as observer point with field attributes for Spot, offsetA, offsetB, Radius1, Radius2, Vert1, Vert2, Azimuth1 and Azimuth 2. For the raster file- a dsm with elevation data. They have the same projection and coordinate system
But when I run the viewshed analysis I get this error:
ERROR 010067: Error in executing grid expression. No valid Observation points present.
Failed to execute (Viewshed).
Any suggestions how to solve this?
Best Answer
For a viewshed to work the Spot values need to be above the elevation shown on the Input Raster. For example a SPOT height of 11.5m within a DTM cell of 12m will cause that error. As an alternative try using an OFFSETA instead of SPOT.