DTM / DEM Generation

Digital Terrain Models (DTM) and Digital Elevation Models (DEM) are essential in providing map accurate imagery as they remove distortions caused by the sensor and topography, which is not possible if correcting the imagery solely to maps. The models are generated from stereo capable sensors on satellites such as Spot, Radarsat and Ikonos.

However, these stereo-capable satellites may not have the spectral resolution required for your project. In which case, Geosense can generate a topographic model, from either the stereo capable satellites or best available topographic mapping by extracting and attributing contours. Then merge the two image types and orthorectify to create a high resolution multispectral image..

Another method for deriving height information is by subtracting the phase of one ERS radar image from another. This method is called Interferometry and is particularly useful in detecting subtle changes in land height such as in subsidence, earthquake and volcanic areas.