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3.MBASUREMENT OF SPECTRAL CHARACTERISTICS ON PADY FIELD 
To monitor a fertilization management for a large paddy field 
and to forecast the rice yield is one of the most desired application 
of the remotesensing technique, as the rice is the main dish in 
daily life in Japan. And the remote sensing can be easily applied 
to a rice field as the rice field is located on a flat field and 
each field is separated clearly from other fields. 
It is the basic requirement to make clear the relation between 
a growing process and a spectral characteristics of the rice. 
So the following three terms were studied for a spectral radiance 
measurement in the rice field, 
(1). The analysis of the relation between the spectral characteristics 
and the difference of the fertilizing status on the fields fertilized 
with the different way. 
(2). The effect of the viewing angle for the spectralradiance 
characteristics of the rice field. 
(3). The analysis of the relation between the spectral radiance 
characteristics and the growing condition which is indicated with 
the Leaf Area Index, the biomass, the horizontal projection area 
and so on. 
And then, the most suitable wave length and range of the remote 
senser for the rice field were studied through the wave length range 
dependency and the change of the season. 
3-1. TEST FIELD 
The test field is located at Inbagun in Chiba-pre., and is one 
of the typical rice field in the rural area of Tokyo. 
Three different fertilizing codrate which were 2 by 2m were 
prepared for this study, and the test field is shown in Table-3-1. 
The field spectral radiance measurement were done every week from 
June 25 ( young rice ) to September 3 ( hearvest ) in 1977. 
The growing status of rice were recorded with the height of 
the rice stump, the number of the stems per the stump, the number 
of the ears per the stump, and the pictures were taken from three 
different directions for the horizontal projection area and for the 
virtical leaf prjection area. 
And the sample rice stump was taken from the test field to 
measure the spectral radiance of each leaf and each ear in the 
laboratory. The Leaf Area Index and the biomass were also measured 
with the sampled stump.