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ESTIMATION OF SURFACE REFLECTION PARAMETERS OVER LAND 
USING LINEAR POLARIZATION DATA BY ADEOS / POLDER 
Kazuya Takemata and Yoshiyuki Kawata* 
Kanazawa Technical College, Japan 
*Kanazawa Institute of Technology, Japan 
Commission VII, Working Group 1 
KEY WORDS: POLDER, ADEOS, Multiple 
scattering, Polarization, Atmospheric effect. 
ABSTRACT: 
In this paper, we show the estimated results of surface 
reflection parameters using the observed reflectance and 
polarization data in visible spectral channels over land 
surfaces measured by the ADEOS/POLDER. The 
parameters are the surface reflectance A and the mixing 
ratio a of the specular components to the diffuse 
components on land surface areas. POLDER level-1 
products over the Sahara Desert in West Africa taken on 
November 18, 1996, were investigated by using a single 
atmospheric layer model with ground surface. We adopt 
the Junge model as an appropriate aerosol size distribution 
model. The simplified Rondeaux - Herman surface model 
is used as a surface reflection model. / 
The main results in this study can be summarized as 
follows: 1) We found that the theoretical model can satisfy 
both the observed directional reflectance and linear 
polarization data. 2) An assumption of Lambertian 
reflection of a desert target seems to be valid in visible 
spectral channels. In this computation, we use the Junge 
model with v — 3 and refractive index m-1.55-0.0051 as a 
typical desert aerosol. 
1. INTRODUCTION 
POLDER instrument was flown aboard the Japanese 
ADEOS satellite. ADEOS was launched on August 17, 
1996, by the National Space Development Agency, Japan. 
But the operations of ADEOS had stopped on June 30, 
1997, by the accident. This satellite has eight sensors. 
The POLDER is one of those sensors and is developed by 
CNES (Centre National d' Etudes Spatiales). This sensor 
observes the polarization and directionality of solar 
radiation reflected by the earth's atmosphere - ground 
system. 
This paper shows the estimation of the surface reflection 
parameters, using ADEOS/POLDER's reflectance and 
polarization image data. The parameters are the surface 
reflectance A and the mixing ratio a of the specular 
components to the diffuse components in the radiation 
reflected by the targets. We have analyzed the airborne 
POLDER data to estimate the parameters (Takemata et 
al., 1997a). We presented the atmospheric correction 
algorithm applicable to the airborne POLDER data, by 
using the multiple scattering theory (Takemata et al., 
1997b). Then we have made the multiple scattering 
analysis for spaceborne POLDER data over the Sahara 
Desert in West Africa (see Figure 1), by introducing the 
combined model with the atmosphere and ground surface. 
  
Sahara 
  
  
  
  
Figure 1 Location of study area. 
2. SPACEBORNE POLDER DATA 
The POLDER instrument consists of a two-dimensional 
CCD matrix detector, a rotating filter wheel, and wide . 
field of view optics. The angular coverage of this sensor 
is X43? in the along-track direction and £51° in the cross- 
track direction. It can measure successively the reflected 
radiation of terrestrial surfaces in a 242 lines x 274 
columns image form (called the "framed image)." The 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 43 
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