TOPODRONE airborne laser scanners can be mounted on almost any type of UAV: - airplane, helicopter, hexocopter or quadrocopter - for surveying area or linear areas. Since the position and orientation of the scanner is constantly changing, TOPODRONE LIDARs are equipped with GNSS receiver and IMU (Inertial Measurement Unit), which measure the position and orientation of the carrier/scanner in space. To improve the accuracy of coordinate measurements, base stations are used, which give a high-precision position in post-processing.
Additionally with TOPODRONE scanner on the UAV can be installed digital photo equipment, which allows you to make aerial photography simultaneously with laser scanning. The range of TOPODRONE scanners is from several tens of meters to hundreds of meters. Accuracy of reflections fixation in height - 5 cm, in plan - 5 cm. Thus, when surveying the terrain from a height of 60-130 meters, the plan accuracy will be no worse than 5 cm. The density of reflections will be from tens to hundreds of points per 1 square meter and depends on the frequency of generated pulses, flight speed and flight altitude. The possibility of capturing several responses from each pulse allows to obtain laser reflections from the ground surface hidden by vegetation, i.e. to reconstruct the terrain where it is impossible to do it with traditional aerial photography. Airborne scanning is used for surveying both area and linear objects, such as roads, pipelines, power lines, etc. The results of airborne laser surveying are used in surveys for design purposes, object inventory, cartography and many other fields. Airborne scanning is superior to mobile scanning in terms of data acquisition speed, but significantly inferior in detail (point cloud density). The main result of laser scanning - whether ground, airborne or mobile - is a cloud of three-dimensional points describing the geometric parameters of the object. The number of laser reflections acquired during the survey of a survey object is often in the hundreds of millions or even billions. Processing of such data arrays and formation of final products on their basis for users in various branches of activity is the most labor-intensive component today. When applying the above mentioned techniques it is possible to use photo cameras instead of a scanner. The most common technique is aerial photography (APS), aerial survey. By photogrammetric methods aerial survey (ASF) is processed by means of software automatic generation of three-dimensional point clouds used both for creation of relief (surface) model and for creation of orthophotomaps. The disadvantage of using photogrammetric methods of point clouds generation is: sensitivity to image quality, dependence on lighting conditions, requirement to follow the survey methodology. Point clouds obtained by photogrammetric processing results significantly lose in completeness and quality to laser scanning data. Airborne scanning data are characterized by high accuracy, possibility to survey relief under vegetation canopy, metal structures, masts.