Point Density
Definition
The number of LiDAR returns per unit area of ground surface, typically expressed as points per square metre. Higher density enables finer DTM resolution and better detection of small-scale features.
- Field
- LiDAR terrain analysis
- Metric
- Returns per unit ground area
- Typical unit
- Points per square metre
- Effect of higher density
- Finer DTM resolution, better small-feature detection
Common questions
Why does point density matter for finding a clandestine grave or disturbed ground?+
A grave-sized depression or mound is a small-scale feature, and a low point density can smooth it out of the derived terrain model entirely, while sufficient density preserves the subtle elevation change needed to flag it for ground search.
Does higher point density always improve detection results?+
Not without limit. Very dense point clouds increase processing time and file size, and if vegetation cover is dense the useful ground-return density can be much lower than the raw point density, so density has to be matched to the terrain and canopy conditions.
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...
- Curvature
- A DTM derivative measuring the rate of change of slope. Profile curvature (along the slope direction) identifies convex mounds and concave hollows....
- Hillshade
- A raster derived from a DTM by simulating illumination from a defined sun position (azimuth and altitude angle). Produces light-and-shadow contrasts that...
- LiDAR (Light Detection and Ranging)
- An active remote sensing technique that emits laser pulses and measures the time of return to calculate distance to reflecting surfaces. Airborne...
- Terrestrial Laser Scanning (TLS)
- A ground-based 3D LIDAR survey instrument that captures millions of range measurements per scan to produce a millimetre-accurate point cloud of the...