LiDARscans

LiDARscans refer to the 3D representations produced by LiDAR scanning. A LiDAR system emits laser pulses and measures the time it takes for each pulse to reflect off a surface, enabling precise estimates of distance. When collected en masse, these measurements form a point cloud that encodes the geometry of the scanned scene.

A typical LiDAR setup includes a laser emitter, a photodetector, and a scanning mechanism to direct the beam. Measurements can be time-of-flight or phase-based. Many systems operate at wavelengths around 905 nanometers or 1550 nanometers, the latter offering higher potential accuracy and greater eye safety. Scanning can be done with rotating mirrors, rotating platforms, or solid-state beam steering.

LiDARscans are produced in several configurations: airborne LiDAR for large-area topography; terrestrial LiDAR (TLS) for detailed scans of buildings and objects; mobile LiDAR (MLS) mounted on vehicles for road networks; and bathymetric LiDAR for shallow-water mapping. Each type yields different point density and coverage.

Data characteristics include 3D coordinates (x, y, z), an intensity value for the returned pulse, and a return number in multi-return systems. Common formats for storage are LAS/LAZ, PLY, and E57. Processing workflows typically include georeferencing with GNSS/IMU data, noise filtering, classification (ground, vegetation, buildings), and surface reconstruction or meshing.

Applications span topographic mapping, flood and hazard modeling, urban planning, construction, forestry, archaeology, and autonomous vehicle perception. LiDARscans support precise measurements, line-of-sight analysis, and change detection over time.

Limitations include occlusion by objects, variability in reflectivity, adverse weather reducing data quality, and large data volumes requiring substantial storage and processing power. Privacy and regulatory considerations also apply in populated areas.

LiDAR technology originated in the 1960s and has since evolved with advances in sensors, positioning technology, and processing algorithms, broadening its use across science, industry, and government.