Surveying services
Surveying with laser scanner or RGB sensor
Effective and fast creation of coloured point clouds
A typical processing workflow for creating a digital terrain model (DEM) is shown here. The starting point is the recording of a coloured point cloud, recorded with a system consisting of the DJI M350 as the carrier platform and the DJI Zenmuse L2 as a laser scanner. The point cloud on the left of the image was corrected for missing points and the georeferencing was optimised.
Point cloud with height colouring
Schematic colouring of the point cloud for efficient data evaluation.
By analysing the z-axis, an effective statement of the height relief can be created in a matter of seconds. The highest points are shown here in dark blue and the lowest in yellow. This display of information is called a digital surface model (DSM).
Automatic removal of surface structures from the point cloud
With the help of machine learning algorithms in programmes such as the LiAir software suite from GreenValleyInternational or VirtualSurveyor, the data can be cleaned up and analysed quickly and efficiently. For example, by automatically removing the surface structures from the point cloud to create a digital elevation model (DEM).
Creation of elevation mapping
With just a few clicks, contour lines can be created from the cleaned and georeferenced point cloud.
Enrichment of the original data set with additional information
RGB-based
Orthophotos generated from drone-based RGB data have many advantages:
high resolution, easy visualisation through 3D models, and low initial investment in hardware and software.
Orthophoto mapping, point clouds, DTM/DEMor DOM/DSM and 3D models can be generated as output. The UAS used for this purpose are usually smaller than the models with laser scanners, which means that the authorisation requirements are often lower.
The precision is comparable to LiDAR scanners in the lower to medium price segment.
vegetation cannot be penetrated, so the automated creation of DEMs is not advisable in areas with high vegetation density
.
LIDAR-based
LiDAR-based drone surveys always generate a point cloud as a product. This can subsequentlybe processed into a 3D model orDEM / DSM data.
A major advantage of LiDAR data is the penetration of vegetation by the LiDAR sensor, which makes airborne LiDAR data particularly suitable for DEM creation in overgrown areas.
Combined surveying approaches from airborne and ground-based LiDAR data
To effectively survey areas that are not visible from the air, handheld or terrestrial LiDAR systems (e.g. LiGrip from GreenValleyInternational) can be combined with airborne systems (e.g. DJI Zenmuse L2) can be combined. In this way, point clouds can be supplemented with the undersides and interiors of structures, buildings and facilities.
