Susumu Hattori
5 EXPERIMENTAL TESTING
5.1 Orientation of a SPOT Stereo Scene
In order to evaluate the applicability of the affine projection model, as well as the other orientation models
detailed above, a first series of tests were made using a SPOT stereo scene over western Japan (see also
Okamoto et al., 1999 and Hasegawa et al., 1999). The two images are shown in Fig.2. These were recorded
in November, 1996 (left) and in February, 1995 (right). The base-to-height (B/H) ratio of the image pair is a
favourable 0.7. Two test sites were selected from the scene. One is a relatively small region called Kobe-AT
(40km x 20km) which covers urban areas, seashore and mountains, with a maximum height difference of 800m.
The other is a larger region called Kobe-Osaka (50km x 60km), which includes Kobe-AT. The maximum height
difference in terrain in this broader region was again 800m.
a) Left ( taken in Nov.1996) i b) Right ( taken in Feb.1995)
Figure 2: SPOT Images Used in Experiment
Orientation was conducted in the Japan Plane Orthogonal (JPO) coordinate system No.V, the projection system
of which is Gauss-Krueger. GCPs and check points for orientation were prepared by aerial photogrammetry for
Kobe-AT, and by photogrammetry and GPS surveying for Kobe-Osaka. Estimates of accuracy of GCPs are
0.3m in planimetry and 0.6m in height. In Kobe-AT, 117 points were utilised, while in Kobe-Osaka 48 ground
points were employed. The heights employed were orthometric heights, though because of the minimal tilt of
the geoid in the area, this aspect was of limited accuracy concern. Image coordinates were measured to 1/4
pixel accuracy by the digital stereo comparator, Kyoto-C (Ono et al., 1999).
— 30km
O9GCPs
+ 6GCPs
® 4GCPs
^ Check Point
/ Flight Direction
of satellite
be
10km
A
9-o
A
| -lOkm
770
— -20km
| | | | |
20km 0 -15km 20km 0 -20km
a) Kobe-AT b) Kobe-Osaka
Figure 3: Disposition of GCPs and Check Points for Kobe-AT and Kobe-Osaka
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000. 363