Y/j/ -Y coordinates of DIN points located on j-line 
parallel to X axis 
Z/i,j/-heights of DTM points. 
Such organization of the model allows for brief data record 
in computer memory and enables quick searching of heights 
- <r 
for required X,Y coordinates of grid points, 
During one of several studies tachymetric measurement was 
performed for the fragment covering area about 100 ha, 
This measurement was done with mean height error 10.10 m, 
Distances between points were about 30 m. These points 
were plotted and their coordinates were read using Codimat 
and next transformed to local terrain coordinate system, 
On the basis of aerial photographs at a scale of 1: 6 000, 
taken by RC-10 Wild camera with focal length 152 mm, for- 
ward overlap 60% digital model was registered in local co- 
ordinate systems,related to different stereograms, in the 
form of square grids 40x40 m in size, After transformation 
heights of points, having tachymetric coordinates, were 
interpolated. Tachymetric heights were subtracted from 
photogrammetric heights, The following magnitudes were 
obtained for 1050 points: 
n 
m=z [aal-ns! + 0,24 m 
n 
vhers: À = 2 + H a height difference 
n - number of points 
S8 - SyStematio deviation 
Ma - Mean error of difference 
Taking into account mean error of tachymetric height m 4 
mean error of interpolated height was estimated: 
2 
my=t\ mtr? =£0.18 n 
i.e. 0.2%0 of flight height. 
- 204 - 
  
  
  
  
SS TCU E RS RR RR Ee SE TC meer ÀÀ.