LiDAR
Definition
Light Detection and Ranging: an active remote-sensing method that emits laser pulses and records the time-of-flight of returning echoes to produce a 3D point cloud of a surface.
- Full name
- Light Detection and Ranging
- Method
- Active remote sensing, laser pulses
- Measured
- Time-of-flight of returning echoes
- Output
- 3D point cloud of a surface
Common questions
Why is LiDAR described as an active sensing method?+
It emits its own laser pulses and measures the returning signal rather than passively recording ambient light or reflected sunlight, which is what distinguishes it from photographic or photogrammetric survey techniques.
What forensic advantage does a point cloud give over photographs?+
A point cloud preserves accurate three-dimensional spatial measurements of a scene that can be revisited and re-measured later, whereas a photograph only records a two-dimensional projection from one viewpoint at one moment.
Related terms
- Bare-Earth DTM
- A digital terrain model produced by filtering LiDAR returns to ground-level pulses only, removing vegetation and structure returns. The resulting surface represents...
- Ground Classification
- The algorithmic process (e.g., using LAStools or PDAL) that separates ground-surface returns from non-ground returns in a LiDAR point cloud, enabling bare-earth...
- Micro-Topography
- Small-scale (centimetre to metre) variations in ground surface height. Grave mounding, subsidence hollows, and soil-scrape scars are micro-topographic features typically invisible to...
- Point Cloud
- The raw data product of a LiDAR survey: a set of 3D coordinates (X, Y, Z) for each laser return, classified by...
- SfM Point Cloud
- A 3D point cloud derived from overlapping photographs using Structure from Motion photogrammetry. Achieves similar resolution to terrestrial LiDAR at close range...