Calculating line of sight

Line of Sight is an imaginary straight line joining the centre of the observer's eye with the object being viewed. Line of sight varies with the source and target location, and are obstructed by taller objects. The Line of Sight command allows you to identify the visible and invisible parts along the line from observer location to destination. The area visible appears is represented by green and area invisible by red.

Figure 296 

An example of line of sight

1.	View the map in 3D mode. For more information, see Viewing the Map in 3D mode.

2.	Navigate to reach the view extent of the 3D map that you want to analyze.

3.	If the Map tools pane is not expanded, in the map viewer, click the Map Tools button.

4.	On the Map Tools pane, click the More Tools button and then select Line of Sight. The Line of Sight dialog box appears.

5.	Click the icon next to the Start Point field and click a location on the map. The Start Point field gets populated by the coordinates of the selected location.

6.	In the Eye Height field, specify height of observer’s eye.

7.	From the drop-down list, select the unit for measuring the water level.

8.	Click the icon next to the End Point field and click a location on the map. The End Point field gets populated by the coordinates of the selected location.

9.	Click Show.