(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
101