The final version of the Planimat is the result M 
of a long series of experiments and several 
prototypes. Its present concept is above all due 
to the collaboration of the author with Messrs. 
H. Urz and G. DnEvzn. But special mention 
should here also be made of the work of | 
W. BAUERSFELD who in the early nineteen- | 
fifties suggested, among other things, an ; 
“instrument for stereoscopic measurements in | 
aerial photographs" in which both single-arm Yb : 
guide rods and double space points were used | | 
[2]. Contrary to the solution now chosen for the 
| 
| 
| 
  
= 
= 
3 
| 
w 
Planimat, a design was described in the corre- | 
sponding patent application in which the 
optical system was moved instead of the photo- N ef | 
graphs, in which the guide rods were suspended | Ei iion. PC 
| 
| 
| 
| 
] 
| 
| 
l 
| 
  
  
instead of resting on a ball at their lower end 
and in which the projection distance z was 
always less than the focal length f. With this | 
arrangement — which did, however, impose 
relatively narrow limits for the z-range — | 
BAUERSFELD tried to keep guide-rod deforma- 
  
  
  
tion to a minimum by reducing the length of A 
the rods. T 
The fact that very similar ideas had already Yk 3 4 
been expressed much earlier, namely in 1913 Xa =f 
by Gustav KAMMERER [3], did not in any way | i. 
diminish the importance which BAUERFELD’s K 
independent considerations had for the latest 
; Fig. 10 Point designations in stereo model; 1—6 for 
ZEISS instrument. 
relative orientation, 3 and 4 in front position of ground 
carriage, facing the operator; A—C for absolute orien- 
; : : : ^ : tation; K position of center of rotation of plotting camera, 
Relative orientation is carried out in the NN straight line connecting the nadir points, KM verti- 
Planimat as in existing stereoplotters, as is cal plane through the left-hand nadir point of the camera. 
obvious from the sequence given under Method ^ The positions of K and NN are marked in the instrument. 
7. Relative orientation 
  
  
Table 1 
Sequence | Method 1 | Method 2 | Method 3 
| Point-No. Element | Point-No. | Element |  Point-No. Element 
| | | 
1 | 1 XB 1 bys 1 XB 
9 2 XA 9 XA 2 X A 
3 8 PB 3 bz A 3 PB 
4 4 QA 4 QA 4 QA 
5 5 wa (Kw) 5 wa (Kw) 5 wa (Kw) 
6 1 Xn 1 bys 1 bys 
7 2 XA 8 bz A 3 bz A 
8 3 QA | 
9 4 PB | 
200