Modern drones (previously referred to as UAV’s – Unmanned Arial Vehicles) now have the ability to quickly and very cost effectively collect highly quality mapping data from smaller areas, areas that have been considered too small to collect using traditional aerial mapping techniques, such as helicopters,
fixed wing aircraft or even satellites.
Combined with the recent advances in software, drone collected mapping data can be processed fast allowing for aquick turn arounds for the client. Drone mapping has proven to be very successful in environmental monitoring, natural disasters such as bushfires and cyclones, as well as insurance inspections to determine the quantity of damage inflicted when these natural disasters occur, especially in areas that are too dangerous for people to enter.
Some of the Industries currently using drone Mapping
The construction industry is currently experiencing a huge take-up of drone data, where maps generated from quickly collected drone data is being used to regularly update clients on the progress of their projects, as well as allowing companies and contractors to analyse stockpiles of materials such as rock, gravel or crushed stone, allowing the client to generate 3D models of their construction sites as well as determine where various pieces of equipment are located so that they can maximise the utilisation of their equipment.
These highly detailed maps help construction managers to quickly get an overview of their sites as well as assisting in strategic decision making.
The drone mapping is much more cost effective that have staff members walking around a site with a clipboard looking for various pieces of equipment and estimated the amount of material sitting in various stockpiles.
Land surveyors are rapidly discovering the benefits of aerial mapping, allowing them to rapidly record property boundaries, as well as assisting in the creation of maps, plots, and legal documentation.
Combined with accurately placed Ground Control Points (GCPs), survey can leverage the power of drones to capture data faster than ever before.
There are some experiments currently underway where surveyors are using drones for “indoor mapping”. This has the possibility to open up areas of mapping that have traditionally very difficult to under take data collection.
An aerial view of a property can really put a property into it’s spatial context with regards to it location. With just a single glance the view can establish how close a property is to a major shopping centre, the distance from the coast or even how close the local parks and natural areas are.
These aerial views can really help to sell a property especially if the property is not easily visible from a public viewing area or when trying to show the potential of a block of land when simulating what the views might be like if a building attains a certain height.
Drone mapping can also aid in the display and surveying of land when trying to establish a new housing development. Having a “big picture” of the entire development can aid both property developers, builders as well as potential purchasers.
The mining industry is rapidly embracing the use of drones as a cost effective way to capture spatial data. The most common usage is in stockpile volume calculations and change in volume reporting.
Until recently, stockpile volume calculations where undertaken using the manual method where one or more surveyors would scramble over the stockpiles recording the shape of the pile. The downside of this method is that its is dangerous for the surveyors, people can slip and fall, as well as it been slow; all the while operations on the stockpile have to stop, causing lost time delays.
When aerial photogrammetry methods are used, the shape of the stockpile can be captured in just a few minutes and production does not have to stop. The “work goes on”.
The drone mapping process
Once a specific ground target is selected and the resolution of the mapping is determined, the drone (or RPA) operator defines a number of “waypoints” across the target area. These wayspoints are defined using GPS coordinates are are spaced sufficiently close enough that there is a considerable overlap between sequential images.
The overlaps must occur between shots on the same traverse line as well as across the lines. These coordinates are then loaded into the drone’s software and the drone then automatically flies to each designated waypoint, stops and records an image of the ground. The aircraft then moves onto the next waypoint and the process continues.
Once the aircraft has landed, each of the individual images are uploaded to
specialist photogrammetry software where a number of different operations can be carried out such as creation of an georeferenced orthomosiac (An orthomosaic is a series of individual aerial photographs that have been programmatically matched up so that they form a new composite image), and the overlap between then images can be used to generate a 3D image of the terrain. The greater the overlap the better the detail.
If the images are captured with the camera point directly downwards then the resultant 3D image will
not display steep or near vertical surfaces accurately. If the images are captured at an angle say 45 degrees, then building and steep terrain can be rendered much more accurately.
Once a 3D terrain model has been generated, the images can be used for generating contours of the ground and used for volumetric calculations.
Other data that can results from the drone mapping can included:
– Point Clouds
– DEM (Digital Elevation Model) /DTM (Digital Terrain Model)
– Extraction of Planemeteric features – such as road edges, heights, building footprints
There are a number of software packages that can process drone imagery into suitable drones mapping data. These packages include :
3DF Zephyr Photogrammetry Software
Open Drone Maps
ESRI’s Drone2Map for ArcGIS
DJI GS Pro
Some videos that discuss drone mapping: