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Photogrammetry Services

TreisTek acquires accurate images of the Earth from a host of sources, such as aerial photography, laser photography and satellite imagery. We offer a complete range of photogrammetric services for municipal mapping, utilities mapping, road and highway planning, cadastral mapping, city modeling, etc. Our services include consulting, project planning, software application development, image acquisition and processing, data conversion and integration.

Photogrammetric Solution and Services offered:

  • Earth imaging services

  • Triangulation – orientation and adjustment of a block

  • Stereo data collection – feature mapping

  • Terrain modelling and 3D visualisation

  • Orthophoto

  • Cartography – map finishing and publishing

  • Thematic mapping using satellite imagery

  • GeoSpatial services for photogrammetry and remote sensing

Photogrammetry Services

Aerial Triangulation

Aerial triangulation is the process of collecting and intersecting points of the same feature on different images and placing points of known coordinates in order to establish the position and orientation of the images at the moment of the camera exposure.

The main objective of aerial triangulation is to produce sufficient points from ground control in the photogrammetric model to ensure that each model can be oriented accurately as required for stereo compilation in either orthophoto or line mapping.

There are mainly three stages of aerial triangulation:

  • Preparation

  • Image measurement

  • Block adjustment


TreisTek's aerial triangulation processing services cover all types of cameras.

Aerial Triangulation


Orthorectification is the process of removing the effects of image perspective and relief effects for the purpose of creating a planimetrically correct image. The resultant orthorectified image has a continuous scale wherein features are represented in their 'true' positions. This allows for the accurate direct measurement of distances, angles, and areas. Orthorectified images are commonly used in visualisation tools such as google earth, OSSIM planet, ArcMap, WMS, etc.

The necessary inputs for orthorectification:


  • An image with accurate sensor geometry.

  • An elevation model of the ground surface in DEM, DTED, or SRTM format.

The resulting accuracy of the orthoimage is based on the accuracy of the triangulation, the resolution of the source image and the accuracy of the elevation model.

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