Create linear lines of sight

Available with 3D Analyst license.

The Linear Line of Sight tool shows the surface that is visible between one or more observer and target locations. Use this tool to locate observation posts tasked with monitoring a specific location, or for test siting of radio antennas. The results show the number of visible targets, sight lines, and a line of sight.

Open the Linear Line of Sight tool

To open the Linear 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 Linear Line Of Sight tab .

Add surface information

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

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

   Note:

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

Input observer and target points

You create linear lines of sight by specifying one or more observer and target locations.

Input points manually

You can add observer and target 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.

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

   On the map, target points are marked with red squares.

Input points from a list

You can add observer and target 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 Linear 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.

4. Copy a list of target point coordinates in which each coordinate pair is entered on a separate line.
5. Click the Target Points drop-down arrow and click Enter Manually.
6. Right-click in the Target Points list box and click Paste.

   On the map, target points are marked with red squares.

Input points from a .csv file

Import a .csv file to add points to the Linear 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.

6. Click the Target Points drop-down arrow and click Enter Manually.
7. Right-click in the Target Points list box and click Import.
8. Browse to the .csv file that stores the target points, and click OK.
9. On the Select Fields dialog box, specify which fields in the .csv file store the coordinates.
10. Click OK.

    Target points are marked with red squares.

Input points from a layer

You can add observer and target 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.
2. Click the Target Points drop-down arrow and choose an available layer.

Enter an output name

You can name your linear line of sight output.

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

Note:

The Linear Line of Sight tool produces a feature dataset in the default geodatabase with four feature classes. The value entered in the Output Linear 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 Linear Line of Sight text box and uses that name.

The Linear 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 and target heights

You can specify observer and target heights for analysis.

1. Expand Observer Options.
2. Change the observer and target information or accept the defaults.
   1. In the Height Above Surface section, enter values in the Observer and Target text boxes.
   2. Click the drop-down arrow to select the unit of measure.
3. Click OK to calculate line of sight.

   In the output layer, if a target is visible to an observer, it is colored green. If a target is not visible to an observer, it is colored red. Visible sections of the line of sight between an observer and a target are green. Sections that are not visible are red.

   Visible targets include a label showing the number of observers that can see them. Lines of sight between observers and visible targets are outlined in white. Lines of sight between observers and targets that are not visible are outlined in black.

   

   In this example, there are two observers and three targets. Only one target is visible and it is visible only to one observer.

   Tip:

   You can refine your analysis by changing offset heights or adding observers or targets.

   Click Cancel to remove the observer and target coordinates from the tool.

Note:

When using the Linear 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.