Thereby, a corrected Crectified) image can be formed 
succesively - pixel by pixel. In in view of numerical procedure 
it is a time consuming process. Therefore, it is applied to the 
reference pixels only (see Fig.3). For pixels which are located 
within that reference mesh, the corrections can be calculated 
using simple interpolation (the bilinear interpolation was 
applied [Schuhr, 1983]. Only central pixel area sized by 3x3 
pixels (see Fig.3) were corrected in this way. For the 
remaining eight pixels, which surround the central pixel, the 
intensity values of gray shade are transfered directly from the 
eight neighbours of central image pixel Ci, 72. 
3. Results of testing 
The proposed method was applied to correction of two scanner 
images taken for two different testing areas. (Image A in FRG 
and Image in Poland). The technical data of the terrain and 
images are listed in table 1. The same [Schuhr, 1983] or 
similar [Rose, 1984] images taken by M^S Bendix scanner, and 
[Babos, 19821 taken by C 5800 scanner were corrected. 
  
  
  
  
  
  
  
  
  
  
  
Table 1 
Technical data of A and B images and field used for testing. 
Image A Image B 
Type.ot data "Freiburg" "Sroda S1." 
1 Data 1976.08.14 1978.07.18 
2 Scanner type field of view M^S Bendix/100 C S00/288,6 
3 Height of flight m 2300 6300 
Speed km/h 240 470 
4 Variation of external high for the high for the 
orientation elements whole scene first 100 lin 
8 Pixel size: 2 1.3 * 2,2 2.6 =x 1.3 
— angular  [mrd ] 
IFOV xIFOV, a-along flight | b-along line 
- terrain at nadir [m^] 3,1 * 5,1 15,4 x 8,2 
— terrain at the end " 
of scan line [m 1 4,8 * 12,3 16,95 8,7 
6 Image size: 
- number of pixel per eoooxeo3 z 1800x384 = 
line x number of lines = 2,3 min = 0,7 mln 
— area covered [km J 9x5,5 = 50 29,5x3,3 = 97 
7 Terrain relief characte- 
ristics:- average slope 7? 19 
— maximal diffe- 
rence in hight 500 m SO m 
8 Number of points used to 
form DTM 195 = 
9 Total number of reference 
and control points 166 114 
  
  
  
  
  
125