Data acquisition for creation of a the Digital Terrain Model (DTM) is performed by 3D photogrammetric techniques using stereo aerial photographs. DTM consists of height points on a regular or irregular grid as well as of brake lines representing gemorphological characteristics and terrain anomalies e.g road edges, building layouts, watercourses, cuttings, embankments, steep slopes etc.

Digital Terrain Models constitute primary importance data sets necessary for a wide range of applications like environmental, energy, hydraulic, flood control and engineering studies.

Creating a DTM within a build-up area, it is necessary to represent also all man made objects forming in this way a Digital Surface Model (DSM) which describes both, the terrain's relief as well as buildings and constructions of any kind making a 3D City Model.

3D City Models are used for a wide range of applications like telecommunications, GSM and 3G prediction planning, noise prediction models, thermal emissions modelling e.t.c

In Geomatics, we produce Digital Terrain Models or 3D City Models as stand alone products for several applications or as base products necessary for production of orthophotomaps.