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V. Concluding remarks
In this paper, general discription of Japanese TM data
processing system and some preliminary results of TM data
evaluations are presented. The TM data processing system is
undergoing final adjustments using NASA & NOAA provided TM
HDOTs. In parallel with the system adjustments, TM data
evaluation is being promoted with a view to reflecting the
results to tne improvement of the system correction accuracies.
In the TM data evaluation, it was found that responsivity
of detector is considerably stable and the pre launch
responsibity data is applicable to correct radiometric distor-
tion.
Calibration lamp data analysis indicated stable character-
istics and the radiometric correction method based upon the
internal calibration system will be developed.
Revealed average radiance difference between forward and
reverse scans indicated the necessity of scan direction
separate radiometric correction. The experiment of separate
radiometric correction showed good results in removing the
radiance difference. The separate radiometric correction will
be adopted to the daily processing system.
It was seen that TM data also contain coherent noises like-
wise MSS data. The effect of the noise to the data utility
should be evaluated.
EXE EU es to Sa ee SS Se EN
Es ES
ELA SR EU
ID
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For geometric correction, the analysis of PCD data showed
a significant relationship between the high frequent spacecraft
oscillations and the scanning of TM and MSS mirrors. Such
analysis will help understanding the nature of geometric
errors,thereby refining the geometric correction method.
We very much appreciated Mr. Iijima (Remote Sensing
Technology Center of Japan) and Mr. Nakahata (Hitachi,Ltd.)
for their help with the experiments.
References
(1) NASA/GSFC:Landsat4 to ground station interface discrip-
tion ,Rev.6/7,1983.
(2) John L.Barker:Analysis of Multispectral Scanner(MSS)
and Thematic Mapper(TM) performance,LTWG,1983.
(3) Proceeding of Landsat 4 early results symposium,1983.
