Toshiaki Hashimoto 
  
satellite position and attitude. Mapping projection is Latitude/Longitude projection for low and middle latitude regions 
and Polar Stereo Projection for high latitude regions. 
2 OVERVIEW OF GLI 
2.1 Characteristics of GLI 
The orbit of ADEOS-II satellite summarized in Table 1 is very similar to that of ADEOS except the recurrent period. It 
is just four days and any point on the earth can be observed three times in four days at least. Main characteristics of the 
GLI are shown in Table 2. The spectral range covers visible (VIS), near infrared (NIR), short wavelength infrared 
(SWIR) , mid and thermal infrared (MTIR) regions. Two kinds of ground resolution are adopted; Ikm and 250m. The 
spectral channels of the 250m channels are almost same as those of Landsat/TM. The GLI is often compared with the 
MODIS which has also 36 spectral channels. The former has 7 channels in MTIR, while the latter has 16 channels. It 
means that major observation targets are the ocean for GLI and the atmosphere and ground for MODIS. As same as the 
OCTS, the GLI has the tilt function for preventing sun-glitter, however, the sensor will not be tilted for land purpose. 
In other words, normally the GLI will observe the ocean with the tilt and the land without the tilt. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
item values item values 
Type sun synchronous, VIS ikm: 13(4), 250m:. 3 (3) 
sub-recurrent spectral channels NIR ikm : 6 (3), 250m: 1 (1) 
Period 101 min. (for land) SWIR 1km : 4 (2), 250m: 2 (2) 
Altitude 803 km MIR ikm : 7 (3) 
Inclination 98.6 deg. resolution at nadir ] km, 250m 
Recurrent period | 4 days swath angle + 45 deg. 
Local time at AM.10:30x15min tilt angle -20 deg., 0 deg., 20 deg. 
descending node quantization bits 12 bits/data 
Table 1 Main characteristics of orbit Table 2 Main characteristics of GLI 
2.2 Land products 
The raw data will be processed to make the Level 1B product of which the registration error and the radiometric 
distortion are corrected. The process of generating the products for land application start with Level 1B product as 
shown in Figure 1. Firstly the Level 1B product is geometrically corrected. This process is the subject of this paper. 
After the process, the data shown in Table 3 are generated. The composite of the geometrically corrected images in 16 
days is generated for cloud screening. The criterion for determining which pixels is selected in the composite image is 
the degree of the cloudiness proposed by another PI. The atmospheric correction is applied to all channels except 
thermal channels of the composite. This product is called as ‘L2A_LC’. The products like land covers, biomass, etc. 
are generated using the L2A LC products. 
  
  
  
  
  
  
  
  
  
  
  
data type bytes/data Level 1B 
image data (all land channels) 2 v 
scan geometry 
solar zenith angle precise geometric correction 
solar azimuth angle, 4 Y 
  
satellite zenith angle, 
satellite azimuth angle 
observation time 
cloud flag 
land/ocean flag 
elevation (only 250m products) 
composite 
* 
atmospheric correction 
land cover, biomass, 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
No |= | |OO 
  
  
Table 3 The summary of geometrically corrected data produces 
vegetation indices, etc. 
  
  
  
Figure 1. process flow forland products 
  
142 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B1. Amsterdam 2000. 
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