s or 
hed 
sub- 
n is 
jn is 
data 
ıting 
; the 
are 
| We 
"OP 
  
  
  
  
  
  
  
Fig.1. Example of division the region with different density of the data points for proper DTM modelling 
using not authentic break lines 
5. SCOP AS A TOOL FOR DATA VERIFICATION 
Problem of gross errors in data especially concern the 
creation of DTM on the ground of isolines' digitization. 
Transformation of isoline drawing from 2D to 3D space 
requires manual typing of hights attributes. It is the 
reason that the gross errors can be easely done. 
The SCOP has a possibility of surface interpolation with 
various filtering of data. This attribute of program is used 
to search for errors. The first run of the calculation of a 
terrain model is performed with such parameters, which 
gives effect of a strong smoothing of surface. Differences 
between hights of calculated surface and hights of data 
are basis for localization of gross errors. Example of 
finding out an error in data is shown in Fig.2. 
  
  
  
— 
  
  
Fig.2. The result of gross errors detection - 
the marked contour line have by mistake the hight 430m instead of 420m 
6. THE USE OF SCOP PRODUCTS IN OTHER 
APPLICATIONS 
We treated SCOP system like a professional, flexible tool 
for solving the most of classical tasks of DTM creation. 
Although we dispose of another software applications for 
663 
this problem (SURFER, MGE Terrain Analyst), after all 
SCOP is superior to them because of it's interpolation 
quality. Therefore we always use that system to calculate 
DTM in the form of grid. On the other hand later we 
export such grid to another systems. Procedures applied 
by us are shown in Fig.3. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996