TarVIS is Visible but VISCode is both Visible and Not Visible

MargoBlosser — Mon, 14 Oct 2013 22:42:49 GMT

I need an explanation about the relationship of the VisCode and the TarIsVis fields. I have an observer and target locations. My TarIsVis says that the target is visible. I would think that my line-of-sight line would be entirely visible (VisCode =1). What I have are two lines with a VisCode = 1 and a VisCode = 2. Most of the line is not visible, VisCode = 2. This does not intuitively make sense. Could someone please explain how this can be the case.

I am using a LIDAR DSM. The LOS calculations are being done with a Geoprocessing service.

Thanks for any information you can provide!

Re: TarVIS is Visible but VISCode is both Visible and Not Visible

XanderBakker — Tue, 15 Oct 2013 11:54:49 GMT

Hi Margo,

The visibility does not refer to a straight line through space between the observer and the target. The line follows the surface (the DSM) and determines for each point on the surface if the observer can see it. See image attached:

[ATTACH=CONFIG]28334[/ATTACH]

Green is visible, Red is not...

Kind regards,

Xander

Some more reading:
Understanding visibility analysis
Creating a profile graph from line-of-sight results

topic TarVIS is Visible but VISCode is both Visible and Not Visible in 3D Questions

TarVIS is Visible but VISCode is both Visible and Not Visible

Re: TarVIS is Visible but VISCode is both Visible and Not Visible