Definition
Scan angle is the angle at which a LiDAR pulse leaves the scanner relative to straight down, or the direction the sensor is pointing. In airborne LiDAR, it describes how far to the side of the flight path a given measurement was taken.
The scan angle matters because measurements taken at steep angles behave differently from those taken straight below the sensor. Understanding it helps ensure consistent, high-quality data across a survey.
In simple terms, scan angle is how far off straight-down each LiDAR measurement was aimed.
How It Works
As a LiDAR sensor sweeps side to side beneath an aircraft or across a scene, each pulse is fired at a particular angle. Pulses near the centre point almost straight down, while those at the edges of the sweep are at larger, more oblique angles.
Larger scan angles mean the laser travels farther and hits surfaces more obliquely, which can reduce accuracy, increase the chance of missing data, and create shadows. Surveys are often planned to limit extreme angles and overlap flight lines so most data comes from favourable angles.
Applications
Scan angle is an important quality factor in airborne LiDAR mapping, forestry, and corridor surveys. Managing it helps ensure even, accurate coverage, reduces gaps and shadows, and improves the reliability of the resulting point clouds and models.
Benefits
- Helps ensure consistent data quality.
- Guides flight planning and overlap.
- Reduces gaps and shadows in data.
- Improves accuracy of point clouds.
- Supports even coverage across a survey.
Related Terms
- LiDAR (Light Detection and Ranging)
- Point Cloud
- Aerial Mapping
- Point Density
Frequently Asked Questions
What is scan angle in LiDAR?
It is the angle at which each LiDAR pulse is fired relative to straight down or the sensor’s pointing direction.
Why does scan angle matter?
Larger angles reduce accuracy and can cause gaps and shadows, so managing scan angle helps ensure consistent, high-quality data.
How is scan angle managed?
Surveys are planned to limit extreme angles and overlap flight lines so most data comes from favourable angles.
What happens at large scan angles?
The laser travels farther and hits surfaces obliquely, which can lower accuracy and increase missing data.
About Track3D
Track3D helps teams turn LiDAR data into accurate digital twins and reality capture insights. Learn more at Track3D.
