3D Modelling & Photogrammetry

The increasing use of UAVs for 3d modelling, photogrammetry and lidar mapping in aerial surveys is not surprising.  Using GPS enabled UAVs for aerial surveying is very cost effective in comparison to hiring an aircraft with photogrammetry equipment.  Because UAVs are relatively inexpensive, many organisations will have their own fleet, allowing for rapid surveys over large land areas where required. 

With GPS-equipped drones, digital cameras and powerful computers, we are able to produce surveys with an absolute accuracy of under 5 cm depending on a number of parameters.

What Exactly Is UAV Photogrammetry

Photogrammetry is the science of making measurements from photographs. The output of photogrammetry is typically a map, a drawing or 3D modelling of some real-world object or land mass.

3D Maps And Models 

To create 3d maps from aerial photogrammetry, the camera is mounted on the drone and is usually pointed vertically towards the ground. Using photogrammetry to create 3D models of monuments or statues, the camera is mounted horizontally on the UAV.

Multiple overlapping photos (80 to 90% overlap) of the ground or model are taken as the UAV flies along an autonomous programmed flight path called a waypoint.  To overlap photos of an object or land by 80 to 90% would be impossible to complete accurately by pilot navigation.  It is essential to have a UAV which has waypoint Navigation technology.

UAV Lidar Mapping Explained

UAV Lidar (Light Detection And Ranging) involves mounting a laser scanner on a UAV to measure the height of points in the landscape below the UAV.

UAVs with lidar scanners can capture hundreds of square kilometres in a single day. By measuring 10-80 points per square meter, a very detailed digital model of a landscape can be created.

The accuracy of the measurements allows the 3D models created to be used in any planning, design, and decision making processes across many sectors.

Lidar sensors can also pierce dense canopy and vegetation, making it possible to capture bare earth structure that satellites cannot see, as well as ground cover in enough detail to allow vegetation categorisation and change monitoring.

Photogrammetry And Lidar Uses 

Through the use UAV photogrammetry and lidar mapping, there are many products which can be extracted from the aerial imagery.  These products include:

  • DEM / DTM / DSM (surface models)
  • Orthophoto’s (geospatially corrected aerial images)
  • 3D Building Models
  • Contour Maps
  • Planimetric features such as road edges and heights, signs, building footprints, etc.
  • 3D vegetation modelling
  • Volumetric Surveys

Here are some of the best uses of lidar and photogrammetry.  All of these sectors benefit for having precision 3D images of their projects.  They also benefit with increased efficiency and reduced costs than using traditional aircraft.

  • Forestry Management and Planning
  • Flood Modelling
  • Pollution Modelling
  • Mapping and Cartography
  • Urban Planning
  • Coastline Management
  • Transport Planning
  • Oil and Gas Exploration
  • Quarries and Minerals (Volumetric’s and Exploration)
  • Archaeology
  • Cellular Network Planning