voltage causes — via an amplifier system — the z-servo motor in the PLANIMAT to eliminate the 
corresponding parallaxes mechanically. Depending on the magnitude of the x-parallaxes still presentand 
the contrast of the individual image portion, different video frequency band widths are used 
and the screen size is varied with increasing correlation. The individual ‘optimal’ degree of cor- 
relation is thereby automatically set via appropriate control circuits. 
4) In close coupling with the correlation process for x, the control of the speed of the y-servo 
motor tor line scanning in the image is, in addition, carried out via corresponding control circuits. 
Fig. 2 Cathode-ray tube K with additional photomultiplier P 
(Sp — semi-transparent mirror) 
light source cathode - ray tube 
Hit 
on 
photomultiplier | e or Z 
— 6€ f zem == fr 
(to correlator) photomultiplier 
  
  
  
  
pholo- TF 
(7 = 
qd X 
e» 
| 
| Cm : 
measuring mark + : 
® 
AD Fig. 3 Schematic diagram of the optical 
evepiece ! ray path in the PLANIMAT (halved). 
Fig. 1 shows the PLANIMAT with Correlator attachment. The units (K) at the sides of the image 
carriages accommodate the cathode-ray tubes. Via the optical systems the scanning points are imaged 
into the viewing path of rays in the right and left image carriage (Fig. 2). On passing through the 
images they reach the photomultiplier tubes (P) arranged above the photo carriers. A small percen- 
119