-5- 
where F equals Focal length of camera 
Z Q - Vertical distance between object and lens 
oo - Rotation of camera around X axis 
cp a Rotation of camera around Y axis 
a - Projection in X-Z plane of inclination angle of light 
ray from object to projection on the plate 
3 B Projection in Y-Z plane of inclination angle of light ray 
from object to projection on the plate 
8 x = Projection in X-Z plane of slope angle with respect to 
horizontal 
9y s Projection in Y-Z plane of slope angle with respect to 
horizontal 
These expressions are valid for the maximum tip and tilt angles of 5° in 
the B-8. The tip, tilt, and inclination angles are sensed with potentiometers 
mounted to the cameras* The outputs of these potentiometers together with 
the slope signals are used to generate the scan correction functions in the 
correction computers* The correction computer outputs thus bring the image 
scale differences between the two plates to a minimum* 
From the foregoing it is seen that if the output from either of the photo 
multipliers P^ or P^ is used to modulate the light output of a third CRT and 
this tube has an unmodified deflection, that a rectified picture will be ob 
tained on its face. This is due to the fact that the pattern used to scan the 
diapositive has received the same changes in scale as the projection of a unit 
terrain area on the diapositive. This third CRT is used to produce an ortho 
photograph in the orthophoto printer. 
It is of interest to note that the basic design principles developed for the 
Stereomat, i. e. : 
Time synchronized random scan patterns on separate cathode ray 
tube s, 
Shaping of scanning raster to accomodate photograph geometry, 
orientation, and terrain slope, 
Modification of raster size as a function of degree of correlation, 
Color separation of coaxial electronic and visual optical systems, 
are now being employed by Bendix Research Laboratories for the automa 
tion of the Analytical Plotter AS-11A. The major difference is that in the