SUBSIDENCE DETERMINATION BY DIFFERENT SENSOR TYPES USING STANDARDIZED TRANSFORMATION PARAMETERS

The mining activities of the German coal mining company Deutsche Steinkohle AG (DSK) lead to subsidence-induced large area influences e.g. to the ground water level or to watercourses. Aerial photogrammetry, and thus Digital Elevation Models (DEM) and stereo plotting of mine heaps and industrial sites, is based on the ‘TP network ’ of the Ordnance Survey of North Rhine-Westphalia (LVA-NRW). The terrestrial survey, and thus line-levellings or site plans, generally base on the local cadastral ‘AP network’. These networks contain differences of about 1 m to each other. Aerial flight campaigns with modern radar or laser sensors are based on GPS/INS data. Spaceborne satellite data will often be geocoded by using the standard DREF transformation parameters set up for Germany that lead to differences of several meters to local coordinate systems. For the combination and comparison of different DEM and other available data like terrestrial measurements, the current ground reference systems and transformation parameters have to be known. According to the recommendations of the AdV [ADV 1995] and [JAHN 2001] a common homogeneous coordinate system with standardized transformation parameters from the “European Terrestrial Reference System 1989 ” (ETRS89) to the “Gauß-Krüger ” (GK) coordinate system (Deutsches Hauptdreiecksnetz 1990, DHDN90) was defined for the mining areas of the DSK