Ono Tetsu
Left Image Right Image
( Black points: Check Points White Points: GCPs )
Figure 2: Test Images and Measured Points
Table 2: Accuracy of Ortho-Image and the Orientation (pixel)
Left Image Right Image
Direction flight | scanning | flight | scanning
Orientation | 0.922 0.524 0.763 0.625
Ortho-Image | 0.923 0.652 0.755 0.711
5 IMPLEMENTATION
The authors developed the digital stereo plotter KYOTO-P, which can handle satellite imagery with 2D afline
projection model. It is mainly written in interpreter language ” Tcl/Tk", but it is fast enough on PC with
Pentium 200Mhz. KYOTO-P uses 3D glasses Crystal EYES for stereo viewing and another special device
is not required. KYOTO-P consists of four components: orientation module, epipolar resampling module,
digital stereo comparator and digital stereo plotter. The whole process is as follows. As the first step, relative
orientation points and GCPs are identified on the original satellite images with digital stereo comparator.
Secondly, epiplar resampling module generates epipolar resampled image based on affine projection. Orientation
calculations are carried out to determine the relationship between the epipolar images and object space. Mapping
operator stereoscopically views the epipolar images, scrolls the images in real-time and compiles topographic
maps on the monitor.
6 CONCLUSION
This paper has reported on the application of the 2D affine projection model to satellite ortho-image generation
and also has referred to real-time positioning. It has shown that 2D affine projection model has advantages in
stability and speed in these application. The model has some limitations in the employment, but the model
are efficiently applicable to small area mapping. Also, our testing has supported the contention that SPOT
ortho-imagery to 1-pixel ground accuracy can be produced using ground control and DTM data from existing
published map of the Japanese large scale map series. Considering the characteristics of affine based approach,
2D affine model is also appropriate for high resolution satellite imagery. Furthermore, the module based on
the model has been implemented easily on softcopy photogrammetric workstations and has worked very well in
Speed.
REFERENCES
D. J. Gugan, 1987, Practical Aspects Of Topographic Mapping From SPOT Imagery, Photogrammetric Record,
12(69): 349-355 (April 1987), pp.349-355
D. J. Gugan and I. J. Dowman, 1988, Topographic Mapping from SPOT Imagery, PE & RS, Vol.54, No.10,
Octover 1988, pp.1409-1414
676 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000.
Df) "F.
RS