Create radial lines of sight

Available with 3D Analyst license.

The Radial Line of Sight tool shows terrain visibility from a location using observer information. Using a surface and one or more observer locations, the tool shows areas that are visible to one or more observers or not visible to any.

Open the Radial Line of Sight tool

To open the Radial Line of Sight tool, complete the following steps:

1. On the ribbon, click the Analysis tab.
2. In the Workflows group, click Visibility Analysis .
3. In the Visibility Analysis pane, click the Radial Line Of Sight tab .

Add surface information

The Radial Line of Sight tool requires surface information to perform calculations.

1. Click the Input Surface drop-down list and select an elevation surface layer from the Contents pane.

   Note:

   The elevation surface layer must be in a projected coordinate system.

   Caution:

   The use of a global or large area extent image service results in excessive processing time. It is recommended that you use a local dataset or a small area extent image service.

Input observer points

You create radial lines of sight by specifying one or more observer locations.

Input points manually

You can add observer locations manually by entering known coordinates or by selecting locations from the map.

1. Click the Observer Points drop-down arrow and click Enter Manually.
2. In the Observer Points text box, enter a coordinate and press Enter to add it to the list. Alternatively, click Observer Map Point Tool and click the map.

   On the map, observer points are marked with blue circles.

Input points from a list

You can add observer locations by copying and pasting a list of coordinates or importing a .csv file.

Input points by copying and pasting

Use copy and paste functionality to add points to the Radial Line of Sight tool.

1. Copy a list of observer point coordinates in which each coordinate pair is entered on a separate line.
2. Click the Observer Points drop-down arrow and click Enter Manually.
3. Right-click in the Observer Points list box and click Paste.

   On the map, observer points are marked with blue circles.

Input points from a .csv file

Import a .csv file to add points to the Radial Line of Sight tool.

1. Click the Observer Points drop-down arrow and click Enter Manually.
2. Right-click in the Observer Points list box and click Import.
3. Browse to the .csv file that stores the observer points, and click OK.
4. On the Select Fields dialog box, specify which fields in the .csv file store the coordinates.
5. Click OK.

   Observer points are marked with blue circles.

Input points from a layer

You can add observer locations by selecting a layer from the Contents pane of a map.

1. Click the Observer Points drop-down arrow and choose an available layer.

Change symbology

You can change the way the Radial Line of Sight tool outputs are symbolized.

1. Optionally, check the Symbolize non-visible data in output check box.

   If the box is unchecked (the default), nonvisible areas are symbolized with no color. If the box is checked, nonvisible areas are symbolized in red.

2. Optionally, uncheck the Symbolize multiple observers check box.

   If the box is checked (the default), visible areas are symbolized differently according to the number of observers who can see them. If the box is unchecked, all visible areas have the same symbol no matter how many observers can see them.

Enter an output name

You can name your radial line of sight output.

1. In the Output Radial Line of Sight text box, enter a name for the output.

Note:

The Radial Line of Sight tool produces a feature dataset in the default geodatabase with two feature classes. The value entered in the Output Radial Line of Sight text box is used to name the feature dataset and is prepended to the feature classes within the feature dataset. If a feature dataset with this name already exists, the tool automatically appends a number to the value in the Output Radial Line of Sight text box and uses that name.

The Radial Line of Sight tool output is added to the Contents pane in a group layer. The name used for the feature dataset is also used for the group layer.

Enter observer information.

You can specify the observer information.

1. Expand Observer Options.
2. Change the observer information or accept the defaults.
   1. Under Height Above Surface, enter values in the Observer and Surface text boxes. Click the drop-down arrow to select the unit of measure for observer and surface height.
   2. Under Distance, enter values in the text boxes for the minimum (nearest) and maximum (farthest) linear distances to be analyzed for visibility. Click the drop-down arrow to select the unit of measure for distance.
   3. Under Field of View, enter values in the Horizontal and Vertical text boxes to constrain the field of view of the observer. Click the drop-down arrow to select the angular units for field of view.
3. Click OK to calculate visible areas.

   Areas visible to an observer are shown in green. By default, if an area is visible to more than one observer, it is shown with a unique color indicating the number of observers that can see it.

Note:

You can refine your analysis by changing the height, distance, or field of view settings.

Click Cancel to remove the observer coordinates from the tool.

Note:

When using the Radial Line of Sight tool in a global or local scene, you must add your own local elevation surface. The default World Elevation 3D/Terrain 3D surface in a scene cannot be used by the tool.