EIS en
TT CR
Dr a A rar Lf
1:5000 and 1:40,000,
The flights were always done so that the targets were
imaged in the same places on the center and the periphery of
the image plane,
3 DETERMINATION OF QUALITY OF AERIAL COLOR PHOTOGRAPHS
3-1 RADIATIVE TRANSFER CHARACTERISTICS (TONE REPRODUCT ION)
The tone reproduction curve of the photography can be
obtained by measuring densities of images of the four steps
grey scale and plotting them against the incident exposures,
Fig, 5 shows the radiative transfer characteristics of
the aerial color photographies taken on both clear and hazy
days.
“
In. order to record information precisely, all information
must be recorded on the straight portion of the radiative
transfer curves.So the radiative transfer characteristics are
desired to have a long straingt portion. From Fig, 5,the
density range, which the aerial reversal color film records
the information with good linearilty, was found to be 0.4-1.4,
Fig. 6 shows the difference of the radiation transfer
characteristic between the center and the periphery of the
image plane.
The central part has better characteristic than the
periphery and the exposure ratio which is necessary to make
same densities on each place was 1:0.74,
3-2 MTF
The images of square wave bar target were scanned by a (9
microdensitometer with a slit of 5 um x 200 um .
Density values were transformed to the effective exposures by
using the above described radiation transfer characteristics of
the aerial color film,
MTF for the square wave were derived by the dffective
exposures with the incident exposures at each spatial frequency,
and converted to MTF for the sinusoidal wave by, the following
equation;
Mu) = = { M(u) + 330) - +M(5u) * eT }
AN . a ° — 9
where, M is response for sinusoidal, M is response for square
wave and u is spatial frequency,