TEST TECHNIQUE FOR CHECKING THE FORWARD MOTION 
COMPENSATION DEVICE IN THE LMK AERIAL SURVEY 
CAMERA SYSTEM 
Verm.-Ing. Ulrich Zeth and Dipl.-Phys. Norbert Diete 
Kombinat VEB Carl Zeiss JENA 
GDR 
Commission I/5 
General considerations of the effect of image motion 
It should be undisputed today that the use of forward 
motion compensators in modern aerial mapping cameras is 
of great advantage. Only these compensators make it possible 
to reproduce the high imaging quality of the camera lenses, 
which can be proved with high-resolution and hence relatively 
insensitive aerial films under laboratory conditions, with- 
out substantial restrictions also under flying conditions with 
the same aerial films.Forward motion compensators thus have 
a decisive influence on the efficiency of the overall photo- 
grammetric process. 
It is obvious from the modulation transfer function of the 
mainly involved transfer components (Fig. 1) that the 
imaging quality is most drastically influenced by forward 
motion. While the MTF curves of lens and film behave asympto- 
tically, the MTF curves of forward image motion irresistibly 
approach zero and thus finally determine the limiting resolu- 
tion of the entire system. This fact is only slightly alleviat- 
ed by the circumstance that because of the film response 
threshold the image motion amount being considered here becomes 
not fully effective photographically (generally the theoreti- 
cally calculated amount is used). The image blur caused by 
forward motion is additionally superposed by effects result- 
ing from lens shutter efficiency, the size of image motion 
itself, and other boundary conditions such as object contrast 
and development. Consequently, as shown in Fig. 2 by the 
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