LiDAR sensors can achieve a range accuracy of 0.5 to 10 mm in relation to the sensor and a mapping accuracy of up to 1 cm horizontally (x, y) and 2 cm vertically (z). This makes them particularly useful as a remote sensing tool for mobile cartography. The absolute accuracy of LiDAR refers to the horizontal and vertical accuracy of LiDAR data. Absolute accuracy is evaluated by comparing LiDAR data with control points inspected on the ground.
The main difference between LIDAR and photogrammetry is, of course, how they capture their data. However, many people still have the false impression that photogrammetric topography doesn't offer absolute accuracy when it comes to bare ground. Lidar is not the same as X-ray vision. Lidar penetrates spaces between foliage, trees, or other flora.
You can map the ground covered with denser foliage, which is a point above photogrammetry. However, keep in mind that if your site is extremely dense with vegetation, you may need to send a surveyor to take some pictures under the tree cover. It is an innovative mapping technology that takes the mobility, accuracy, time savings and cost-effectiveness of topography to a higher level. This is what LiDAR looked like when most of its development began in the early 1960s, shortly after the invention of the laser.
The good news is that it has continued to play an essential role in making life easier for engineers and surveyors, and in making general managers in a wide range of sectors more attractive. Point clouds are a non-intrusive way to accurately measure the properties of buildings or objects in 3D. It is not necessary to close places such as hospitals, schools and sports facilities to be able to measure them. Instead, those measurements can be taken after closing time, during downtime, or outside business hours.
3D point cloud data measurements from our SLAM-based scanners can achieve topographic-grade accuracy. There are 4 main parts of an airborne LiDAR that produce a vertical accuracy of 15 cm vertically and 40 cm horizontally. It sends more than 160,000 pulses per second. This is why LiDAR point clouds create millions of points.
Depending on the environment in which the scanning is performed and the specific characteristics of the 3D laser scanner, an accuracy of 0.002 to 0.197 can be achieved. This high level of accuracy helps ensure that measurements are correct the first time, so that less work is needed to complete the subsequent design and production steps. In addition, LiDAR eliminates the human element from the process, making the data even more accurate. Learn about the accuracy of GeoSlam's handheld laser scanners here.
The relative accuracy of LiDAR refers to the internal quality of LiDAR elevation data without using the inspected ground control points. The following table shows the LiDAR point density recommended by the American Society for Photogrammetry and Remote Sensing (ASPRS) for terrain mapping with LiDAR. For example, the accuracy requirements of LiDAR data for the detailed design of infrastructure, such as a dam, may be higher compared to LiDAR data for agriculture.