Visibility Analysis / Join Raster

AsayoHirata — Fri, 22 Nov 2024 16:17:14 GMT

Dear Esri community,

first of all: My english got a little rusty over the years, but please bear with me.

I'm quite new to learning and using ArcGIS Pro, and I was asked to perform a visibilty analysis for a race track. For this task I have 3 features/datasets at hand:

- a DEM raster dataset (elevation model) of the survey area: (the attribute table contains the attributes "Object_ID"; "Value" with the z-values and "Count", which says how many cells with the same z-value exist in this raster dataset)

- a line/polyline feature showing the race track

- a polygon feature with the existing forest areas in the survey area (the attribute table shows 4 attributes: "object-ID", the attribute "forest" with value 1 for forested areas and 0 for unforested areas, as well as "shape_length" and "shape-area")

My task is to show, from which surrounding areas the race track can be seen, considering the view point of a human to be 1,5 meters above ground level, considering forested areas to be 20 m in hight and considering the race track to be 1 meter above the ground. I basically know how to use the "visibility" tool but I have problems preparing the data to do so, since the "forest" polygon layer doesn't contain any hights. I already converted the "forest" polygon layer into a raster dataset with the same cell size as the DEM elevation model but now I don't know how to add the 20 meter offset to the cells, which are considered "forested" (value 1 in the "forest" polygon feature and the converted "forest" raster dataset). Do I need to merge the two raster datasets into one or am I thinking too complicated? If I need to merge them, which tool do I need to use? Questions over questions so thank you all in advance for your kind help!

Greetings

Asayo

Re: Visibility Analysis / Join Raster

Robert_LeClair — Tue, 03 Dec 2024 22:55:36 GMT

I think one change to your workflow is to use a DSM (Digital Surface Model) instead of a DEM (Digital Elevation Model). DSM's account for bare earth, manmade structures and vegetation such as trees. DEM's only show bare earth. So if you use a DSM for your project area, it already takes into account the height of structures or forest areas. In the GP tools, you can expand the Observer parameters to take into account a human at 1,5 meters too as OffsetA

Are you using the Visibility GP tool from the Spatial Analyst toolbox or the 3D Analyst toolbox?

topic Visibility Analysis / Join Raster in ArcGIS Pro Questions

Visibility Analysis / Join Raster

Re: Visibility Analysis / Join Raster