Viewshed Analysis results in truncated coverage at the US/CAN border

AdrianSolomon

Hello, I need assistance understanding why the results of my viewshed analysis shows the "coverage volume" being truncated at the US/CAN border (see screenshot of the lower-right Stickpin). All other viewshed analyses performed results in coverage volumes in US and Canadian geographies (Orange). However, when applying the same approach, I cannot seem to get a coverage volume that is "complete" for said Stickpin (Magenta). Any idea why this is?

Thanks for your help!

 

XuguangWang

Hi Adrian,

It looks like there may be some data discontinuity issue with the 10m DEM data used in this analysis. In North America,  currently the 10m data is only available in the US area.

The Orange viewshed result is fine because it is based on 24m DEM (or 30m DEM) that is available for both US and Canada.

The DEM source resolution used in the analysis is determined by the Maximum viewing distance parameter. If the maximum viewing distance is 5 km or less, 10m resolution is used. If it is greater than 5 km, 24m resolution will be used. (Note: the DEM resolution info is recorded in the output viewshed feature layer attribute table, which you can open and examine).