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Laser ScanningA laser image is multitude of points on the ground surface (laser points) that reflect laser beams emitted by a laser locator. Every point has its specific spatial coordinates X, Y, Z. All taken together, laser points from a certain image of a scene being observed, and it is this image that is defined as a laser image or a cloud of laser points. Than collected laser data could be used for creating Digital Terrain Models and Digital Surface Models. There are airborne and terrestrial laser scanners; accordingly there are airborne and terrestrial laser scanning technologies. Airborne Laser Scanning
Airborne Laser Scanning carries out at a height of 500-1500 meters. Laser scanning accuracy depends on cruising altitude. Average accuracy of spatial coordinate measurements is 15 cm, maximum achievable accuracy up to 5 cm.
Technology advantages:
Airborne laser scanners are often used in combination with medium scale digital photo cameras. In this case, digital aerial images are taken concurrently with laser scanning from the same aircraft. Collected laser data could be used for imagery correction to produce true orthophoto.
Terrestrial Laser Scanning Terrestrial Laser Scanning allows a greater density and accuracy of laser reflection points and, therefore, a higher degree of detail of survey. Terrestrial Laser Scanning can be used to survey and generate models of terrain and areas where all microforms and complicated terrain features are to be included.
Technology advantages:
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