38 
ck 
p 
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pd 
  
le 
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The results of this restitution are for example: 
= orthophotos and digital height models as data base 
for TOPAS, which with ihe CONT program and the 
DZT 90 x 120 is capable of automatically producing 
= graphical representation of profiles, 
= digital height models for off-line orthophotography 
(DETO program of the TOPAS program system). 
1.2. Functional characteristics of TOPONMAT B 
  
   
     
  
Given homologous image areas the electronic correlation 
circuit checks the video signals of the left and right 
photographs for x parallaxes which represent theneelves 
in the video signals as phase shift between tw imilar 
signal sequences and, in dependence on these phase 
shifts, it controls the electrical z drive in the 
plotter so that the ascertained x parallax becom 
by the relative shift of the image i 
For the video signal acquisiti { 
Spot scanning system with two 
photomultipliers,. 
The possible scanning 
are 2 mm x 1 mm, 3 mm 
signals to be correla 
shaping by 3 band pas 
ranges, so that the © 4 T 
cesses digital signals. The digital hardware correlation 
enables fast and reprodudible Selucrons capable of being 
readily handled in the process echnology. Furthermore, 
the CROMAT has a series of au tomat ic functions for 
adapting the system to the different conditions in the 
photographs, These automatic funotions refer for example 
t0 the function parameters scanning raster size, cor- 
relation frequency range and y scanning speed which can 
be selected by the operator. The automatic functions 
correct the performed settings in accordance with the 
situation and simplify the operation. 
A new and important functional unit fn TOPOMAT B is the 
automatic y residual parallax correction in the image 
correlation system, The task of this unit is to guaran- 
tee y residual parallaxes of less than + 0.04 mm referred 
to the image in the second photo car rieT pair. The device 
for the automatic y residual parallax correction is Se ss 
Signed so that it still compensates y residual parallaxe 
up to about + 0.15 mm referred to the image plane. From 
this results the important advantage that the demands on 
      
the optimum y parallax-free orientation of the photo- 
graphs are decisively alleviated, When the p. correction 
is switched off, the y residual parallax qualitatively 
indicated on a measuring instrument is available for sup- 
porting the orientation process in the rear image pair. 
A technique for reducing the correlation failur i 
volves, however, a qualitatively new tion in TO Be