topic Re: Viewshed 2 Failure when Analysis Type is Observer in Public Safety Questions

Viewshed 2 Failure when Analysis Type is Observer

SamChan1 — Sun, 13 Nov 2016 19:52:27 GMT

When I do a Viewshed 2 analysis with Analysis type set to Observer, I get an error: "The table was not found. [VAT_Viewshe_dem37]". The analysis will run without error if the analysis type is set to frequency. Any idea what I am doing wrong?

Thanks for the help.

Sam

Re: Viewshed 2 Failure when Analysis Type is Observer

DanPatterson_Retired — Mon, 14 Nov 2016 03:02:11 GMT

where to start....

Viewshed 2—Help | ArcGIS for Desktop

How Viewshed 2 works—Help | ArcGIS for Desktop

more details will be needed on inputs... and if you are using esri grids... I couldn't help notice the extremely long grid name being used.

Re: Viewshed 2 Failure when Analysis Type is Observer

SamChan1 — Mon, 14 Nov 2016 04:17:55 GMT

Dan. Thanks for the reply. The DEM I am using is a raster dataset. I've looked over the two links you sent and ran Viewshed 2 again using the same inputs that I used previously. There are only 3 points in the input. I first ran it using perimeter sightline and the tool ran successfully. Then I changed it to all sightlines and, again, it ran successfully. I am fairly certain that I did not do anything differently other than the analysis method. So although I am able to get viewshed 2 to work, it is annoying that I don't know why it is working now. The next thing that is puzzling me is the observer value of -1 for all observers in the Value Attribute Table.

Re: Viewshed 2 Failure when Analysis Type is Observer

DanPatterson_Retired — Mon, 14 Nov 2016 04:38:02 GMT

a visual of the results and table would help... -1 normally means 'not' as in not seen, can't see or something like that, such as an area can be seen by one observer, but not another and vice versa to differentiate it from areas that can be seen by both

Re: Viewshed 2 Failure when Analysis Type is Observer

SamChan1 — Mon, 14 Nov 2016 04:58:07 GMT

Here are the associated viewshed 2 results and the VAT. There appears to be regions visible by multiple observers so I don't understand why the VAT table is showing -1 for observers for all the regions.