Drone topography, also known as aerial survey, is a method of collecting data with the help of drones and specialized cameras. It is mainly used by surveyors and engineers in the construction industry for land assessment and cartography. Drone topography can be done 90% faster than traditional surveying methods, making it a popular choice for companies looking to recognize errors in the workplace, track work progress, predict delays in schedules, and more. The collected data is processed using drone mapping software to create construction assets such as 3D models, 2D maps and digital elevation models, from which high-precision volumetric measurements and calculations are performed.
The drone collects high-precision data quickly, without the need for surveying personnel to walk over hazardous terrain or heights to collect the data. Drone mapping drones are made of red, green and blue (RGB) visual images for photogrammetric, thermal, LiDAR or multispectral sensors to collect aerial data. The various maps or results collected from drone topography are orthomosaic maps, the digital surface model (DSM), the digital terrain model (DTM) and contour maps. To perform a very precise topography with drones, it is essential to accurately indicate the position of a drone in flight.
This can be done using ground control points (GCP), a real-time kinematic study (RTK), or a kinematic post-processing study (PPK). GCPs are known points available on the ground whose coordinates are known. GCPs allow the drone to provide accurate data about its location and the distance it moved between the two locations. PPK topography is a GPS correction technology that rectifies drone location data only after collecting and conserving the final survey data. This method helps reduce field time and survey costs while providing accurate and comprehensive data.
However, despite all the advantages of UAV technology, not all mapping and topography operations have fully adopted drones. The main disadvantages of drone surveying include their small payload capacities, difficulty in recognizing terrain characteristics without symbols, and the need for experienced surveyors or cartographers to learn how to use drones in industry. Additionally, capturing precision is a challenge for many people looking to use drones in topography and mapping. A company that specializes in drone technology will be able to help a construction company comply with regulations related to drone use, as those regulations may change given the relative novelty of drone technology. Ultimately, workflows should be developed from the point of view of topography, and pilots who are dedicated exclusively to drones should work to collaborate with surveyors rather than trying to face the industry as an individual. The efficiency and results provided by the drone survey greatly benefited sectors such as mining, urban planning, agriculture, irrigation and the geospatial industry.
