Integration between ground mobile mapping and aerial mobile mapping
Future surveying projects are going to be digital by using new techniques. The most common techniques are ground mobile mapping and aerial mobile mapping, but there are some different advantages and disadvantages to using these methods. By the way, future surveying projects will be unmanned.
Al-Qotr Surveying Company started providing these services a long time ago.
Aerial Mobile Mapping (Drone)
Drone photogrammetry is a measurement technique that make sit possible to model a 3D space using 2D images acquired from a drone. By knowing the position and orientation of each image in space, a three-dimensional position can be calculated for each point of the terrain visible in several images, thus building a cloud of points. This 3Dreconstruction process is analogous to the functioning of our brain which interprets in three dimensions what our eyes perceive from different points of view. processes make it possible to derive other products from the point cloud, such as a photorealistic 3D mesh, a digital surface model (DSM), digital Terrain model (DTM), 3D as-built modeling, digital maps, and an orthophoto.
Ground Mobile Mapping
The mobile mapping system is composed of one or two high-performance laser scanners, a panoramic camera, planar cameras, as well asvarious sensors to precisely determine the trajectory followed. Only a good calculation of the trajectory ensures quality geo referencing of the various products, since both the points measured by the scanners and the images are projected along this trajectory. Being equipped with laser scanners, the point cloud is obtained directly by LiDAR, an acronym for light detection and ranging(detection and estimation of the distance by light). Georeferenced and oriented panoramic images are used as visual support.
Aerial Mobile Mapping (Drone) -3D Point Cloud
Ground Mobile Mapping - 3D Point Cloud
Different and complementary methods
Drone photogrammetry is useful for projects that require a visual 3D representation of large areas.
It offers a wide range of applications, such as the integration of a construction project into its virtual environment, the updating of certain layers of cadastral information, and simulations on an urban scale
Mobile mapping is particularly suitable for mobility specialists, both in the road and rail sectors. the low measurement noise, the accuracy of the angles and the fineness of the digitized objects make it possible to satisfy customers with particularly high requirements in terms of precision and measurement around the project area.
Panoramic images serve as a source of visual information by providing elements that can be interpreted by the human eye.
The ground mobile mapping ensures a high quality of the cloud near the road and the aerial mobile mapping (drone)completes the model on the rest of the territory.
Mobile Mapping System can serve specific projects such as: Streets, railway, inside cities and the Drone Mapping can serve projects that need to capture views from the air.
The image above illustrates the extent of the point cloud acquired by drone (in blue) and that acquired by mobile mapping (in yellow).