A line-of-sight analysis in ArcGIS involves examining the visibility between two points, revealing which portions of the surface along the line are visible or hidden from an observer. By creating a line of sight, you can determine if a specific point is visible from another point. This analysis takes into account the terrain and identifies any obstructions that may hinder the line of sight.
A line-of-sight analysis can be useful in various scenarios, such as:
- Urban planning—You can assess the visual impact of proposed buildings or infrastructure projects on the surrounding environment. For example, determining if a new high-rise building will obstruct the view of a famous landmark.
- Security applications—With the help of line of sight analysis, you can evaluate the visibility between different positions, understanding potential obstructions, and planning strategic movements.
- Telecommunications and broadcasting—You can find the optimal locations for cell towers or radio antennas to ensure effective coverage and minimize signal obstruction.
To perform a line-of-sight analysis in ArcGIS, you typically need access to a digital elevation model (DEM) representing the terrain elevation and any other 3D object or building layer that represent features on the terrain.
Workflows
You can do an interactive line-of-sight analysis in ArcGIS or use the geoprocessing tools in 3D Analyst extension to generate sight lines and create a feature class along which visibility has been determined.
Interactive line-of-sight
ArcGIS Pro, ArcGIS Earth, and applications built with the ArcGIS Maps SDK for JavaScript, such as Scene Viewer, Instant Apps and Experience Builder, offer interactive tools for exploring line-of-sight. The visibility between the observer and multiple target points is calculated against the currently displayed content in the view, including ground, integrated meshes, and 3D objects, such as buildings or trees. The line-of-sight analysis appears as lines: green lines are the visible part that the observer can see; red lines are the occluded part. Both the line-of-sight observer and target locations can be interactively moved through the view.
Besides interactive placement of the observer and target points, there are several other methods In ArcGIS Pro and ArcGIS Earth to create a line-of-sight such as using the camera as the observer and creating an animated line-of-sight along a selected line.
Line-of-sight analysis
The results produced by interactive line-of-sight tools are strictly visual, rendered dynamically and quickly by the GPU. As analyses are evaluated, results are rendered in the scene view for display only. This is ideal for use cases that require interactive and visual evaluation of results that change frequently. If your workflow requires features as output, use the Line-Of-Sight geoprocessing tool in the 3D Analyst extension. This tool calculates intervisibility between the first and last vertex of each line feature given its position in 3D space relative to the obstructions provided by a surface or multipatch feature class.
Consider creating sight lines with the Construct Sight Lines geoprocessing tool if the observer location is identified by point features and the visibility targets reside in a different feature class.
Considerations
Interactive line-of-sight tools use the data currently available in the scene view to perform the analysis and then quickly render the result. Because the data in the scene view changes according to the level of detail (distance of the camera to the surface), the analysis results may change as you interact with the scene view (for example, zoom in or out, change camera tilt, and so on).
Consider using the Analyze Visibility task in the Development Impact Analysis solution if you require a quantitative measurement of visibility. This task calculates the perceived and actual visible area of the target as an attribute of the observer. Distance and angle are considered when calculating perceived visibility because targets that are further away and under an angle from the observer appear smaller.
You can also do a viewshed analysis in ArcGIS. Viewshed analysis highlights areas in the scene that are visible for a given observer, while a line of sight shows which segments are visible along a line drawn between an observer and a target location.
Required software
ArcGIS Pro, ArcGIS Earth, and applications built with the Maps SDK for JavaScript, such as Scene Viewer, Instant Apps, and Experience Builder, offer interactive tools for exploring line-of-sight. You will need ArcGIS Pro with 3D Analyst to analyze line-of-sight and persist the results in a geodatabase. An ArcGIS Online or ArcGIS Enterprise account is required to publish and share the analysis layers as a 3D scene service across your organization.
Explore the following resources to learn more about conducting a line-of-sight analysis in ArcGIS.
ArcGIS help documentation
Reference material for ArcGIS products:
- Interactive line of sight in ArcGIS Pro
- Add a line-of-sight layer in Scene Viewer
- Create a line-of-sight analysis in ArcGIS Earth
- How line-of-sight works in ArcGIS Pro
- Overview of the Visibility toolset in ArcGIS Pro
- Line Of Sight tool in ArcGIS Pro
- Exploratory analysis tools in ArcGIS Pro
- Common exploratory analysis workflows
- 3D Analyst extension
ArcGIS blogs, stories and technical papers
Supplemental guidance about concepts, software functionality, and workflows:
Videos
Esri-produced videos that clarify and demonstrate concepts, software functionality, and workflows:
Tutorials
Guided, hands-on lessons based on real-world problems:
ArcGIS solutions
Industry-specific configurations for ArcGIS:
Esri training
Authoritative learning resources focusing on key ArcGIS skills:
Developer resources
Resources and support for automating and customizing workflows:
Esri community
Online places for the Esri community to connect, collaborate, and share experiences:
- Ask the 3D community questions.