| | Multispectral Channels || Stereo Channels] 
MS1 MS2 MS3 MS4 ST6 Sit 
NJ Ax|Ay || Ax| Ay | Ax| Ay | Ax| Ay Ax|Ay|| Ax| Ay 
25/-0.1-0.7||-0.2/-1.0/-0.3/2.2 |-0.4/0.7 |-0.1/-7.0/10.0/0.7 
225/|0.0 |-0.6/1-0.1-0.7|-0.2/2.1 |-0.2/0.6 ||-0.1-6.9/10.010.6 
425/10.0 -0.6/-0.1-0.5/-0.2/2.0 1-0.1/0.5110.0/-6.8/10.010.5 
625/0.0 -0.610.0 -0.4/-0.1|1.9/0.0/0.3//0.0/1-6.71/10.0/0.4 
8250.0 -0.7/0.0 -0.3/0.0|1.9/0.0/0.2//0.0/1-6.710.010.3 
1025/0.0 -0.7/0.0-0.2/0.0/1.8/)0.1/0.1/-0.1-6.6]/0.0/0.2 
1225/|0.0}-0.7/|0.0}-0.1//0.1/1.7//0.1/0.1//0.0/-6.5//0.0/0.2 
1.7 
1.6 
  
  
  
  
  
1425/0.0 -0.7,|0.0/0.0 !0.1 0.1/0.010.0.-6.5/0.0/0.1 
1625/0.0 -0.7/0.1/0.1]|0.1 0.1 -0.1/0.0 -6.4//0.0|0.0 
1825/0.1 -0.70.1/0.2/|0.1|1.5]|0.2 |-0.2]|0.1|-6.4/|0.0 |-0.1 
2025/0.1 -0.7/0.1/0.3||0.1/1.4]|/0.2 -0.3| 0.1|-6.3/|0.0 |-0.2 
2225/0.0 -0.7/0.1/0.3//0.1]1.4| 0.2 -0.4| 0.1 -6.3|0.0]-0.3 
2425/0.0 -0.7/0.1/0.3//0.1/1.4]|0.2 -0.5]|0.0/-6.2]|0.0 |-0.3 
2625/0.0 -0.7,0.1/0.4//0.2]1.3|/0.2 -0.5]|0.0 -6.20.0|-0.4 
2825/0.1 -0.7/0.1/0.5|/0.2 1.3//0.2 -0.610.0 -6.2//0.0 -0.5 
3025/0.1 -0.7/0.0/0.5//0.2/1.20.2-0.7]|0.0 -6.2/-0.1.-0.6 
3225/0.0 -0.7,0.0/0.5//0.2]1.1| 0.2 -0.7]| 0.0 -6.3-0.1|-0.6 
3425/0.0 -0.6/0.0/0.5//0.2/1.1/|0.2 -0.7,0.0 -6.3|-0.1|-0.6 
3625/0.0 -0.5/0.0/0.5//0.1/1.1/|0.2.-0.8/|0.0|-6.3||-0.1|-0.5 
3825/|0.1 -0.5/0.0/0.5 /0.1/1.1/|0.2 -0.8/0.0]-6.3|-0.1.-0.5 
4025/0.1-0.5/10.0/0.5/0.0|1.1]|/0.1/-0.8/|0.0 -6.4/-0.1|-0.4 
4225/0.1-0.5/0.0/0.4//0.0]1.0/|/0.1|-0.9]|0.0 -6.5,/0.0|-0.3 
4425/0.1 -0.4/0.0/0.4/-0.1/1.0]|0.1|-0.9]-0.1.-6.6/0.0 -0.2 
4625/0.0 -0.3/0.0/0.4|-0.1/0.9//0.0 -0.9-0.1-6.6//0.0 -0.1 
4825/0.0 -0.3/0.0/0.4|-0.1/0.910.0 -0.910.0 -6.7/|-0.1,0.1 
5025/0.0 -0.2/-0.1/0.3|-0.1/,0.8 0.0.-0.9/0.0 -6.7]/0.0|0.2 
95225/-0.1-0.2:-0.1/0.3/-0.1/,0.8/0.0)-1.0/0.0 -6.8]|0.0 0.4 
5425/-0.2-0.1/-0.1/0.2 |-0.1/|0.7/|0.0 -1.0]|0.0)-7.00.0/0.6 
5625/-0.3-0.1/-0.2/0.2 |-0.1/0.6 |0.0 -1.0]|0.0-7.10.0/0.9 
$|0.1/0.1//0.1/0.1//0.1/0.0/||0.0/|0.5|]0.0|0.1][0.3[0.2 
710.020.03/0.030.06/0.0300.02/0.0200.02/0.030.02/0.06/0.08 
CICS X E i i NO 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Table 2: Correction table for multispectral and stereo chan- 
nels [pixel] 
long, the ICC is successfully engaged in Digital Photogram- 
metry and has built up a large digital data base comprising 
full coverage of Catalonia with DTM and color DOI in scale 
1:25000 (ground pixel size: 2.2 m) and 70% coverage of 
B/W DOI in scale 1:5000 (ground pixel size: 0.5 m). Thus, 
the idea was born to try the automated extraction of ground 
control information from this data base by use of the multi- 
scale matching (see subsection 3.1). The DTM has been de- 
rived from aerial frame camera images of scale 1:22000 and 
is stored in the database at 15 m grid size. The accuracy is in 
the range between 0.5 m and 2.0 m. From cooperation be- 
tween the ICC and the Servicio Autonomo de Geografia y Car- 
tografia Nacional of Venezuela, the ICC also disposes of DTM 
(30 m grid at 6 m accuracy) and DOI in scale 1:25000 (1.8 m 
ground pixel size) of an about 12 000 km? wide area around 
Caracas. The two test-sites "Catalonia" and "Venezuela" 
(see Figure 5 and Figure 6) will be imaged at highest priority 
whenever the actual weather and sun elevation allow for good 
illumination and cloud-free conditions. It is planned to cover 
them both from ascending and descending orbit paths in the 
stereo mode A, combining high resolution nadir and the two 
off-nadir stereo channels. In addition the test-site Catalonia 
will be covered in stereo mode D, combining the blue and 
near infrared nadir and the two off-nadir stereo channels. 
94 
  
[: High Resolution Channel ry 
HR5A HR5B 
N || Ax | Ay N Te Ax Ay 
25 01 -0.2 4501 0.3 0.0 
225 0.0 -0.3 4700 0:3 -0.1 
425 0.0 -0.3 4900 0.3 -0.1 
625 -0.1 | -0.3 5100 0.3 -0.1 
825 0.0 -0.2 5300 0.3 -0.1 
1025 0.0 -0.2 5500 0.3 0.0 
1225 0.0 -0.2 5700 0.3 0.0 
1425 0.0 -0.2 5900 0.3 0.0 
1625 0.1 -0.1 6100 0.2 0.0 
1825 0.1 -0.1 6300 073 0.0 
2025 0.1 0.0 6500 0.2 0.0 
2225 0.1 0.0 6700 0.2 0.0 
2425 0.1 0.0 6900 0.2 -0.1 
2625 0.1 0.1 7100 0.3 -0.1 
2825 0.1 0.1 7300 0.2 -0.1 
3025 0.1 0.1 7500 0.2 -0.2 
3225 01 0.1 1100 0.2 -0.3 
3425 0.1 0.1 1900 0.2 -0.3 
3625 01 0.2 8100 0.2 -0.3 
3825 0.1 0.1 8300 072 -0.3 
4025 0.1 0.1 8500 0.2 -0.3 
4225 0.1 0.1 
4425 0.1 0.1 @ 0.4 0.2 
4500 0.1 0.1 c 0.09 | 0.05 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Table 3: Correction table for high resolution channel [pixel] 
3.1 Multi-Scale Matching 
In essence the principles of the image matching software used 
here for the multi-scale matching are the same as have been 
already used extensively for the automated parallax measure- 
ments in MOMS-02/D2 imagery. This software package for 
intensity based image matching has been developed at DLR 
and described e.g. in [8]. 
As MOMS (and also other along-track stereo scanner 
projects) uses a higher resolution for the nadir looking sensor 
than for the inclined sensors (MOMS-resolution ratio is 1:3, 
plans for MOMS-03 aim at 1:2) this software has been gen- 
eralized for multi-scale matching. This extension is described 
here. The local least squares matching (LLSM) which is the 
last step in our current matching procedure anyhow estimates 
a local affinity transformation between the image chips of a 
stereo pair. This LLSM has been generalized to accept scale 
parameters different from 1 as input and to do an aggrega- 
tion of the higher resolution pixels for comparison to the gray 
values of the lower resolution for the computation of the in- 
tensity based observation equations or - if the observation 
equations should be formed at higher resolution - generates 
high resolution from low resolution by bilinear interpolation. 
See Figure 7 for a graphical representation. Ideally, both di- 
rections of resolution change should be done by taking the 
point spread function of the instrument into account or by 
some sinc function, respectively. But in reality the gray val- 
ues have substantial noise added (e.g. instrument noise, ra- 
diometric calibration insufficiencies). Thus this sophistication 
does not pay off for our application and we just use averag- 
ing and bilinear interpolation. The new procedure was already 
successfully applied to MOMS-02 imagery of the Andes [9]. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B1. Vienna 1996 
  
  
Figure 
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