In: Wagner W., Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
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SURF matching error(shear 0.2, building) outliers 7/214 
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SURF matching error(scale 0.6, building) outliers 3/88 
Figure 3. SURF image matching results for (a): 0.2 image shear, 
and (b): 0.6 times image scale difference 
SURF matching error(scale 0.6, building) outliers 0/57 
(b) 
Figure 4. RANSAC tests for (a): 0.2 image shear, and 
(b): 0.6 times image scale difference 
4.2 EOP Simulation 
The platform modeling test was performed using simulated data. 
The camera specification used for simulation is presented in 
Table 2. 
Camera type 
Pushbroom 
Focal length 
79 mm 
Pixel size 
40 micron 
Image size 
Row: 1280, Col: 320 
Imaging rate 
80 lines/sec 
Table 2. Camera specification 
While most matching points are reasonably accurate, several 
low accuracy points are observed; the number of outliers with 
accuracy of lower than 5 pixels is shown at the title. Obviously, 
they should be filtered out to be used as ground control 
information. Therefore, RANSAC was tested for the same data 
set and the accuracy is shown in Figure 4. Note that low 
accuracy points and outliers are successfully removed. Most 
points show matching accuracy less than one-pixel. These test 
results show the potential of the method for matching between 
HSI and satellite images. 
SURF matching error(shear 0.2, building) outliers 0/156 
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Given reference EOPs, the INS-only EOPs were simulated 
assuming drift errors. During 16 sec (1280 lines), the position 
error was simulated to increase to 8 m and the attitude drifted 
reached 0.25°. The simulated EOPs are shown in Figure 6. 
4.3 Platform modeling test 
The ground control points are normally generated by image 
matching based on SURF with RANSAC between the aerial 
pushbroom and satellite images. For this study, a total of 186 
ground control points were simulated in an irregular distribution, 
as shown in Figure 5. 
The INS-only EOPs are used as initial EOP values for the 
platform trajectory modeling. The EOPs estimated using the 
GM model are presented in Figure 6. Perspective center 
positions follow the initial EOPs values but the attitude 
accuracy slightly improved. The yaw angle could be estimated 
well. 
ROW 
Figure 5. Distribution of simulated ground control points 
(assumed generated by the image matching)