Radial Line Of Sight (Defense Tools)

Summary

Shows areas visible to one or more observer locations.

Usage

To add observer points by known coordinates or to set a horizontal or vertical field of view, use the Radial Line of Sight tool on the Analysis tab, using the Visibility button. That tool also offers an option to symbolize the output based on the number of observers that can see an area, and an option to symbolize data that is not visible to observers.
A viewshed is created by finding the areas visible from one or more specified observer locations.
Intermediate datasets are projected to a localized Azimuthal Equidistant projection to maintain fidelity of distance and direction.
The output area polygons will have a Visibility field containing the number of observers that can view a given area.
Using a surface and one or more observer locations, the tool will create areas that are visible to one or more of the observers or not visible to any.
The tool uses earth curvature and refractivity calculations if the input surface supports them.

Label	Explanation	Data type
Input Observer Features	The input observer points.	Feature Set
Input Surface	The input elevation raster surface.	Raster Layer; Mosaic Dataset; Mosaic Layer
Output Visibility	The output polygon feature class showing visible and nonvisible surface areas.	Feature Class
Radius Of Observer (meters) (Optional)	The radius of the analysis area from the observer.	Double
Observer Height Above Surface (meters) (Optional)	The height added to the surface elevation of the observer. The default is 2.	Double

arcpy.defense.RadialLineOfSight(in_observer_features, in_surface, out_feature_class, {radius}, {observer_height_above_surface})

Name	Explanation	Data type
in_observer_features	The input observer points.	Feature Set
in_surface	The input elevation raster surface.	Raster Layer; Mosaic Dataset; Mosaic Layer
out_feature_class	The output polygon feature class showing visible and nonvisible surface areas.	Feature Class
radius (Optional)	The radius of the analysis area from the observer.	Double
observer_height_above_surface (Optional)	The height added to the surface elevation of the observer. The default is 2.	Double

Code sample

RadialLineOfSight example 1 (Python window)

The following Python window script demonstrates how to use the RadialLineOfSight function.

import arcpy
arcpy.env.workspace = r"C:\Data.gdb"
arcpy.defense.RadialLineOfSight(r"C:/RLOS_Observers",
                                "Elevation_Dataset",
                                "RLOS_Output", 5000, 2)

RadialLineOfSight example 2 (stand-alone script)

The following example uses the RadialLineOfSight function in a sample workflow script.

# Import system modules
import arcpy

# Set environment settings
arcpy.env.workspace = r"C:/Data.gdb"
arcpy.env.overwriteOutput = True

# Select points from observers from input
observers =  "Observers"
branch = "Branch"
whereClause = "Marines = 'Yes'"
arcpy.analysis.Select(branch, Marines, whereClause)

# Create Radial Line Of Sight using Marine observers
in_observer_features = "Observers"
in_surface = "Elevation_Dataset"
out_feature_class = "RLOS_Observers_Marines"
radius = "METERS"
observer_height_above_surface = "METERS"
arcpy.defense.RadialLineOfSight(Observers,
                                Elevation_Dataset,
                                RLOS_Observers_Marines,
                                1000,
                                2)

Environments

Output Coordinate System, Current Workspace, Scratch Workspace

Licensing information