Drones have become an important tool in surveying. iC has been using them for several years to create high-resolution terrain models and orthophotos for flood modelling and action planning.
Types of drones and their use
A distinction is made between multicopters and fixed-wing drones. Multicopters are standard for surveying tasks and, depending on the model, can also carry heavy payloads such as LiDAR. Fixed-wing drones enable longer flight times and the efficient coverage of large areas, but require suitable take-off and landing facilities.
Flight planning and data basis
Before each mission, the flight route, flight altitude, image overlap and legal requirements are defined. The software calculates the flight duration, number of images and ground sample distance (GSD). A GSD of 2 cm means that one pixel in the aerial image corresponds to 2 cm on the ground.
Photogrammetry, elevations and evaluation
Photogrammetry is used to create digital models such as point clouds, 3D models, DEM/DTM, contour lines and orthomosaics from overlapping aerial images. Ground control points (GCPs) are used for absolute heights. On this basis, volume calculations as well as cross-sectional and longitudinal profiles can be derived, for example for construction progress and documentation.
Conclusion & outlook
Drones are an integral part of modern surveying. They enable efficient data collection and provide a precise basis for planning, modelling and construction supervision. With ongoing technological developments – such as AI-supported evaluations, automated flight routes and real-time analyses – their range of applications will continue to grow. The surveying of the future will increasingly take place in the air.
