Drone topography, also known as aerial survey, is a method of collecting data with downward-facing sensors using drones and specialized cameras. It is mainly used by surveyors and engineers in the field of construction for land assessment and cartography. Drone topography can be done 90% faster than conventional surveying methods, and is used to make high-precision maps and topography points. Companies use drone mapping 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 (GCPs), 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. The use of drones in geographic information systems (GIS) offers significant advantages for end users, such as remote cartography, faster mapping times and 3D models based on aerial maps. Recent advances in sophisticated 3D mapping technology and GIS drones, combined with the growing market for industrial drones, have made the use of drone mapping technology accessible to a wide variety of companies, beyond the main companies in the sector, with capital for cutting-edge cartographic solutions. Cartography with unmanned aerial vehicles (UAVs), or drones, uses photogrammetry to capture cartographic data from 2D images taken when the drone flies over a project site.
As the drone travels autonomously, following a pre-programmed flight path over the site, it takes multiple overlapping photos with a specialized camera or set of cameras. With 3D mapping technology, these images are joined together, providing accurate measurements of length, area and volume or even complete 3D models of an area. The result is a high-quality aerial map of the location, complete with measurements, that project managers can immediately use for site planning and management. Drone mapping is used in numerous industries, including agriculture, construction, and oil and gas. In the real estate industry, drones are sometimes used to create high-fidelity 3D maps of a given property, allowing real estate agents to offer potential clients a view of the building and the land, even if they can't be there in person. Despite these advantages, there are some drawbacks to using drones in mining and quarrying operations.
First, drones can be expensive to buy, operate and maintain. In addition, drones may not be able to effectively survey certain sites due to their small payload capacities or difficult terrain. In addition, drone technology is still in its infancy and cannot yet offer the same level of accuracy as traditional surveying methods. Nowadays anyone who can afford to buy or rent the right drone and necessary technology can use drones for aerial mapping. Drones are very affordable compared to other surveying and inspection techniques. To perform highly accurate drone inspections it is essential to accurately pinpoint the position of a drone in flight.
Drones can be used to quickly survey large areas without personnel onsite; identify potential hazards; collect data on production; measure stocks; inspect inaccessible areas; reduce field time; reduce survey costs; provide accurate data; and more. However there are some safety concerns when using drones for mapping purposes. The inspection team works in remote areas where accidents are more likely. In addition Federal Aviation Administration (FAA) regulations limit drones from flying at altitudes greater than 400 feet above ground unless they remain less than 400 feet from a structure. Drone data is also susceptible to theft or hacking so it's important to take security measures seriously. The speed of deployment of drones combined with their flexibility make it possible to map almost anywhere at any time.
Drones can be used to quickly survey sites; identify efficient routes for shipping extraction and delivery; create high-fidelity 3D maps; measure stocks; inspect inaccessible areas; reduce field time; reduce survey costs; provide accurate data; improve operational efficiency; and more. Despite these advantages there are some drawbacks that should be taken into consideration when using drones for mapping purposes. Drones may not be able to effectively survey certain sites such as densely forested areas or sites with difficult terrain. In addition they may not be able to provide the same level of accuracy as traditional surveying methods.
