(1)Radiometoric distortion compensation evaluation 
In case of radiometrically corrected imagery (level 1), it 
was confirmed that residual radiometric distortion( RMS of the 
difference of neighboring intensity) were 0:75,0.:67 ,0.25,0.38.:for 
band 1,2,3 and ! which meet the one quantized level. 
(2)S/N evaluation 
By applying the two dimensional Fourier transformation to 
uniform area such as snow field, S/N are 24.0,24.7,24.0,21.5 4B 
for band 1,2.3 and 4,respectively. 
(3)Geometric distortion compensation evaluation 
The geometric compensation accuracies measured by using 8-10 
GCPs 4.7km,46m,17m for level 2,3 and 4 were obtained which is 
under the specified value T.5km,50m,25m for level 2,3 and 4, By 
eliminating bias error of attitude, the position error for level 
2 decreases to be 666m. 
(4)Spatial resolution evaluation 
By using edge in reclaimed land in Tokyo Bay, line spread 
function (LSF), modulation transfer function (MTF)were obtained. 
Example of MTF is shown in Fig.3. In Japan it is very difficult 
to find uniform area neighboring to edge. So, it is necessary to 
develop method applicable to non uniform area. 
3.2 VTIR 
The VTIR is a mechanical scanning type radiometer to observe 
in one visible (band 1:0.5-0.7km) and three thermal infrared 
bands (band 2:6.0-7.0pm,band 3:10.5-11.5pm,band 8:11.5-12.5Hm). 
The nominal spatial resolution is 900m for band 1 and 2700m for 
band 2,3 and 4 ‚The main objective of VTIR is to observe sea 
surface temperature, cloud,upper atmosphere and others. 
(1)Radiometric distortion compensation evaluation 
By comparing VTIR data and VISSR data for uniform sea, it was 
confirmed that radiometoric distortion is under two quantized 
level. When VTIR thermal band was evaluated by using standard 
black body, this distortion was found to be under one quantized 
level. 
(2)S/N evaluation 
Three methods : Mean-deviation method , APR (Adaptive Peak 
Rejection) method and one dimensional Fourier transform method 
were applied to VTIR data in uniform sea area to obtain S/N. By 
using mean-deviation method, S/N are 20.2 dB, 33.6 dB, 43.2 dB 
and H2.9 dB for band 1,2,3 and H, respectively. It was confirmed 
that S/N for band 3 is larger than that for band 4. This is 
because atmospheric transparence is larger in band 3 than in band 
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