2. Japanese earth resources satellite-1 (JERS-1) 
  
JERS-1 is a remote sensing satellite designed to gather image 
data which are useful to explore earth resources. It will be 
launched in 1992 in Japan. Its:weight is- 1.4. tons and the 
altitude of its orbit will be 568 km. 
JERS-1 has two kinds of imaging systems. One is synthetic 
aperture radar (SAR) and the other is optical sensor. The 
wavelength of SAR is L band and the resolution of SAR image 
is 19 m. The swath width“ of both. sensors is (75 km. The 
ground resolution of optical sensor is 18.3 mx 24.0 m for 
the nadir looking sensor and about 19.1 m x 24.0 m for the 
forward looking sensor. The nadir looking sensor stakes 
seven band images ^in the wavelengths of visible, near 
infrared and shortwave infrared. The forward looking sensor 
takes one band image in shortwave infrared wavelength. 
The combination of a nadir looking sensor image and a forward 
looking sensor image produces stereoscopic vision. The 
base-to-height ratio of JERS-1 stereoscopic images is fixed to 
0.3. This ratio can not be enlarged because the nadir looking 
sensor and the forward looking sensor must be placed in the 
same telescope due to considerations of weight limitations etc. 
3. Development of a system to make JERS-1 simulation 
stereoscopic images. 
  
  
We developed a system to make JERS-1 simulation stereoscopic 
images from photographs by computer. The quality and 
usefulness of JERS-1 stereoscopic images can be investigated 
using the output of this system. Figure 1 shows the general 
flow of this system. The details of the components of this 
figure will be explained next. 
LFC photo. (Large Format Camera photo.) 
The input image data of this system is photographic, parti- 
cularly by LFC photograph taken from the space shuttle.  LFC 
photograph is very suitable for this system because it 
covers a very large area with high ground resolution (about 
15 ^ 20 m) similar to JERS-1 stereoscopic images. Moreover 
a photograph has another merit in that the image distortion 
of a photograph can be corrected more exactly than that of a 
satellite image. 
Digital image 
The input LFC photograph is converted to a digital image by 
drum-scanner. 
  
Exterior orientation parameters 
The exterior orientation parameters are extracted from a 
positive-film of the LFC photograph using the aerotriangulation 
method. 
  
110