lead to better results in computer classification of rocks. 
    
  
  
  
   
   
   
  
  
  
  
   
    
  
  
   
  
   
   
   
  
  
  
     
  
  
For the image enhancement and classification procedures a TR 440 
digital computer was used. The results were stored on magnetic 
tape and a hard copy of the processed imagery was produced 
on a HELL Chromagraph. At the moment, an interactive image 
processing system is being installed, the use of which will 
speed up considerably the image classification process. 
Ground truth measurements in the field were conducted in order 
to determine the spectral response of the rock surfaces. In 
addition, readings of the infrared radiation, the surface tem- 
perature, air temperature, relative humidity, wind velocity 
and the elevation above sea level were taken at each point. 
Color photographs were made and samples collected for 
documentation and later analysis. All these parameters were 
then stored on punched cards; a program was developed for 
calculation of the absolute values and plotting of histograms. 
These field parameters were used in the digital classification 
program in order to get more information on the actual spectral 
signatures of the rocks and the mixed signatures mentioned 
above. 
The cartographic techniques by which these maps (KLITZSCH & 
LIST 1978, 1979) could be produced and printed in a rather 
short time have already been described elsewhere (LIST & 
POHLMANN 1976; HELMCKE, MEISSNER, PÜHLMANN & ROLAND 1978). 
Each of the published map sheets (fig.6) at a scale of 
1:500 ooo covers 70.000 sq.km and is printed in 7 colors: 
The LANDSAT mosaic forming the topographic base in violet, 
prominent beds and cliffs in brown, roads and geological 
boundaries in grey and structural lines and names in black. 
The lithologiy, subdivided into 31 units, is printed from 
3 base colors (LIST & PÓHLMANN 1976). 
Only 18 months after the first field party had started, the 
four map sheets as shown in fig.1 were available in printed