L 
e 
Fig. 7 shows MTF of the aerial color films photographed by 
the RC-10 aerial camera with a haze cut filter $420, MTF's 
decrease rapidly at the spatial frequencies 10-15 lines/mm, 
this is probablly occurred due to the lower MTF of the aerial 
camera. 
MTF of across the flight direction did not so much 
decrease at higher spatial frequency compared with that of 
along the flight direction. This seems to be caused by the 
forward motion during the exposure a forward motion compensation 
device. 
From Fig. 7, 4 80-394 color film has the highest MTF and 
next, type 2448. The lowest MTF was obtained for aerial 
color negative film type 2445, because the MTF measure- 
ment were performed for a color positive printed from the 
negative which has one more step as compared with reversal 
films. 
Fig. 8 shows differences of MTF between the center part 
and the periphery of the image plane for the reversal color film. 
The center part has higher MTF than the periphery, and MTF along 
the flight is higher than that of across the flight. 
Fig. 9 shows the effect of the haze cut filter on MTF, 
MTF obtained by installing a single filter no. 420 was higher 
than that of the combination filter of two Wratten filters. 
This is considered to be due to the thickness of the glass 
plates which were used to make the sandwitch filter rather 
than the optical properties of the gelatine filter. The haze 
cut filter affects MTF of only one sensitive layer of the 
color film, because of its absorption band near 450 nm, 
From the remote-sensing viewpoint, the aerial color film 
is considered to be an imaging sensor of three spectral bands, 
and is frequently scanned by a drum scanner to get digital data 
for an automatic computer processing. 
In this case, MTF of the color film becomes a very important 
factor for determing the size of the scanning aperture of the 
drum scanner, which affects the accuracy of the automatic 
pattern recognition. 
Generally, the automatic recognition becomes very erratic 
when the response value of the object to be identified is over 
1.4 times that of that trainning area. This means that, the 
automatic recognition is not applicable when the image quality 
of the target is different from that of the same target of the 
trainning field. 
The factor 1.4 is equivalent to 3 dB and to 70,7 $ of the 
maximum response were derived as Table 1 from the Fig. 6.