LiDAR is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light. Air laser scanner generates a large amount of data that creates a point cloud. It is an accurate representation of the land surface and crosses well the vegetation to reach the ground. A point cloud is used when creating DTM and DSM and vertical terrain profiles. A point cloud is gaining even greater value when the object classification is applied (buildings, water, vegetation levels). This allows to create vector objects, eg. 3D city models.
The accuracy of a point cloud is determined by the density of points per m2:
- 20-12pt / m2 - dedicated to specific models, eg. power lines, urban architecture,
- 12-6pt / m2 - accurate calculation of the earth mass, accurate mapping of details of urban areas,
- 6-2pt / m2 - basic needs, allwoing to get a general and quite precise model.
OPEGIEKA usues Aerial Laser Scanner Riegl LMS Q680i - see more.