I'm trying to find carry out a viewshed analysis but am not able to get consistent results.
Having tried and failed with viewshed and viewshed2 I discovered interactive viewshed analysis in ArcGIS Pro 2.5.0. This appeared promising but having input an observer offset of 10m and using the Ordnance Survey's 50cm DSM as the ground layer I was surprised to see the viewshed change as I zoomed the camera out (using the "C" shortcut to change the cursor to explorer mode). The ground layer uses EPSG: 27700 for the coordinate system and EPSG: 5701 for the vertical coordinate system. I'd like to know why this is happening as it makes any output from this tool unusable.
lots of options here, any particular settings you are using?
and at the very bottom there is this note...
Visual inaccuracies can appear as the viewshed's analysis range ratio increases.
Thanks for the quick response Dan. The settings I'm using are below:
It seems that the tool is working off the pyramids rendered rather than the actual data values.
Thanks for trying Dan. I'm struggling to think of a use case for a "sometimes" accurate analysis tool. Do you have any experience with the viewshed or viewshed 2 geoprocessing tools? I tried both prior to using the interactive one but had very mixed results.