Elevation Data

Ultra high resolution elevation models make their mark

Terrain Model Imagery

While colour and NIR imagery are being captured, our advanced survey guidance and sensor technology is quietly doing a whole lot more. Images are captured with overlap between frames in the forwards and side direction, together with advance Inertial Measurements and GPS data. Our photogrammetrists then use this data to attempt the extraction of elevation for each image pixel using advanced geometric calculations. Pixel then have a height value and together with their neighbours form a surface model.

Each application of this technology can be different. For example, an environmentalist might be interested in the heights of the vegetation canopy while a mine site surveyor is more interested in the bare earth heights. Specialised data filtering algorithms and machine learning tools allows the extraction of above ground features such as vegetation to produce different elevation models.

Outline offers several different elevation data products depending on the level of detail and accuracy required for a particular project. Some products are produced from a fully automated workflow, while other products are the result of a full manual 3D vector mapping workflow.

Dense Surface Model (DSM)

  • Typically generated at ½ to ¼ of native image resolution using GPU-based processing
  • Represents terrain (ground) features, as well as above ground features such as vegetation, buildings and other man-made infrastructure.
  • Similar in nature to raw data product derived from LIDAR data
  • Fully automated workflow with very limited manual intervention or data filtering.
  • Some Gaussian smoothing may be applied to improve viewability
  • Good for line of sight and general ‘lie of the land’ analyses
  • Will not represent all above-ground vegetation and building features in full as algorithm is optimised for ground feature mapping.
  • Cost effective product for whole project areas.
  • Typical output resolution is 5 to 10 times image resolution
  • Typical relative accuracy of 2 pixels or better RMSE.
  • Absolute accuracy dependant on availability and density of ground control data – see accuracy table

Ultra Dense Surfact Model (uDSM)

  • Most accurate and detailed DTM, but highest cost elevation product
  • Derived via a full manual 3D vector mapping workflow, including interactive mapping of 3D breaklines at full image resolution to provide a very accurate DTM product
  • Above ground features such as buildings, fence lines, pipelines etc. can also be mapped and attributed.
  • Vertical and horizontal accuracy is suitable for detailed engineering projects
  • Ideal product for volumetric analysis and ‘as built’ terrain for active mine sites and building sites
  • Typical relative accuracy of better than 1 pixel RMSE
  • Absolute accuracy dependent on availability and density of ground control data – see accuracy table

Dense Terrain Model (DTM)

  • Fully automated product derived via applying automated vegetation and building vegetation filters to the DenseDSM product
  • Gaussian smoothing may be applied to improve viewability of end product
  • No manual 3D breaklines or hydrological features mapped or enforced
  • Good for general planning and relief mapping
  • Cost-effective product for whole project areas
  • Typical output resolution is 5 to 10 times image resolution
  • Typical relative accuracy of 1 to 2 pixels RMSE.
  • Absolute accuracy dependant on availability and density of ground control data - – see accuracy table

Ultra Dense Terrain Model (uDTM)

  • Most accurate and detailed DTM, but highest cost elevation product
  • Derived via a full manual 3D vector mapping workflow, including interactive mapping of 3D breaklines at full image resolution to provide a very accurate DTM product
  • Above ground features such as buildings, fence lines, pipelines etc. can also be mapped and attributed.
  • Vertical and horizontal accuracy is suitable for detailed engineering projects
  • Ideal product for volumetric analysis and ‘as built’ terrain for active mine sites and building sites
  • Typical relative accuracy of better than 1 pixel RMSE
  • Absolute accuracy dependent on availability and density of ground control data – see accuracy table

Contours and Relief Mapping

One of the key advantages of using Outline Imagery is the accuracy and clarity of the stereo imagery collected. This in turn means that the quality of derived products such as elevation models an contours are superb.

Contours are often the most universally common ways of interpreting maps to gauge the lie of the land. Contours generated from elevation models are only as good or accurate as the underlying data, an important consideration if this data is used for detailed planning.

Many other useful features can be derived or interpreted from god quality elevation models, these include;

  • Drainage maps
  • Infrastructure mapping
  • Vegetation disturbance mapping
  • Landform cross-sections
  • Building footprints
  • Road and pipeline corridors profiles

Accurate Survey Grade Data

Large Scale Modeling

Advanced feature filtering

Multiple Delivery Formats

Interested in working with us

Our elevation models stand out for accuracy and detail, no compromise