- 543 - 
DATA ACQUISITON & DATA BASE OF SPECTRAL SIGNATURE in JAPAN 
y.EMORI & y.YASUDA 
Institute of Color Technology, Chiba Univ., Chiba Japan 
m.FUJIMOTO & h.YAMAMOTO 
Asia Air Survey Corporation, Tokyo Japan 
j. IISAKA 
Tokyo Scientific Center, IBM JAPAN, Tokyo Japan 
1, INTRODUCTION 
Generally speaking, a spectral radiometric measurement has two 
purposes. 
At first, it is required to get a fundamental data for correction 
of a remote sensing data,which has a sun angle or an atmospheric 
effects. And it is required to find the best suitable wave length 
range for a given objects' analysis and classification. 
The other is to collect the basic data for a mathematical 
distribution model of a crop, a soil, a mineral, or a water resources, 
and for its simulation with a given sample. 
On this point of view, the following items are required for a 
spectroradiometer: 
(1). Wave length range: the wave length range should be decided 
according to the objects, e.g. 400 to 1100 nm is required for moni- 
toring the forest, the grass, or the vegetated area, or 400 to 700 nm 
is enough for monitoring the water resourses. 
(2). Measuring speed: when the weather on the observation area 
changes so often like Japan, it is required for the radiometer to 
measure in a short time for all wave length range, although the 
measuring speed depends on the detectors ability or on the electric 
circuit of the radiometer. 
(3). Portability: it is required for the radiometer to be a 
battery operated one when the electric supply is not avairable, or 
it is required to be light or to be small when the measurement is 
carried out on the high position. Like this, the more portable, 
the better, although the portability depends on its facility. 
Here, an automatic field spectroradiometer and a battery operated 
hand spectrometer are designed. And the open-air spectral data on 
a paddy field and on a wheat field are collected and discussed for 
the application. 
And the data base, which can easily be used by the end-user 
through the terminal, is explained. 
2. SPECTRORADIOMETER 
2-1. AUTOMATIC SPECTRORADIOMETER 
For practical use, the automatic spectroradiometer, which has a 
short measuring time and an easy handling operation, are designed. 
The schematic diagram of this radiometer is shown in Fig.2-1. 
The radiation from the target are collected by the objective lens, 
and focussed on the field aperture through the beam splitter. 
There are small integrate sphere, which integrates the incident 
radiation, behind the aperture. The radiation from the exist 
aperture pass through the interference filter, which is between two 
small aperture, fall on the UV sensitized Si-cell sensor.