Roessner, Sigrid 
  
the Maili-Suu river basin (Fig. 1). Like the whole region, this test area is part of the active tectonic collision zone 
between the Eurasian and the Indian Plates. Ongoing tectonic activity results in an active development of the Pamir- 
Tien Shan orogen causing earthquakes and mass movements (landslides, rock falls). Landslides mainly occur at 
elevations between 700 and 2000m in weakly consolidated sediments of the topographically rising rim of the Fergana 
Basin below its transition into the high mountainous terrain. 
72*30'E 73*00' E 73?30' E 
   
   
   
    
   
    
    
    
     
  
    
Position of GPS points 
X Plain 
+ Valley 
Oo Hill slope 
Test area X — Hill top 
Maili-Suu 
  
aZ Reference lar oo 
m stations N 
MOMS-2P 
DEM 
Kilometers 
  
ay 30° 
20 0 
  
  
  
Fig. 1 DEM (50m raster size) derived from stereoscopic MOMS-2P data overlaid by GPS check points 
2 INPUT DATA FOR DEM GENERATION 
Remote sensing based DEM generation requires stereo image data, precise 3-D coordinate information of ground 
control points (GCP) and independent check points (CP). MOMS-2P data were acquired in stereo mode D on the 29^ of 
June 1998. Topographic ground control information were obtained by geodetic GPS observations in July 1999. In the 
following two sections both input data sources are described in more detail. 
21  MOMS-2P data 
MOMS (Modular Optoelectronic Multispectral Scanner) is a German spaceborne pushbroom scanner for high 
resolution (HR), multispectral (MS) and threefold along-track stereoscopic imaging (Kaufmann et al., 1989; Seige et al, 
1999), The stereo-module consists of a HR nadir looking lens with a focal length of 660mm and two inclined lenses 
with 237mm focal length. Thus, the Earth’s surface is imaged three times from three different directions within 
approximately 40 seconds only, corresponding to an orbital distance of approximately 300km. This along-track stereo 
principle is highly advantageous for image correlation in the data evaluation process, since all three image strips are 
recorded under more or less the same imaging conditions. The stereo angle of 21.4° results in a base/height ratio of 
approximately 0.8. The multispectral-module consists of two additional lenses with 220mm focal length comprising 2 
CCD arrays for narrow-band image acquisition in the blue, green, read and near infrared wavelength ranges. 
  
1260 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.