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Figure 1.
4. Example: MEOSS airborne data strip Dorfen
4.1 Image material and image matching details
The data strip Dorfen can be seen in Figure 1. The
images of the foreward, nadir and backward looking
sensors are shown in parallel strips of simultaneously
acquired image lines. The along-track displacement
between the images of the same objects (one base
length) corresponds to about 2400 image lines. The
platform, sensor and image parameters are displayed
in Table 1.
The numbers of points extracted by the interest opera-
tor and being left after the digital image correlation are
given in Table 2 for the five levels of the resolution
pyramid.
For the manual start at lowest level of resolution 52 and
33 conjugate points were extracted from the back-
ward/nadir and forward/nadir stereo pairs, respective-
ly. The difference in the numbers can be explained by
the different information content of the stereo pairs.
Data of MEOSS Satellite Model Flown on Board of Aircraft D-CHET of
DLR x
.
P Bua X E s
inadir Looking! LCD $ (backward Looking!
number of CCD elements:
size of CCD elements
71
relatiue radiometric decalibration
3236 stereo look angle: 23.52 deg
18,7 Hm 2m by 2m image processing? DLR-DIBIAS / Le
ground resolution! 2
MEOSS Dorfen strip
Platform Parameters
ground speed
altitude
660 km/h
11335 m
Sensor Parameters
objective
focal length
stereo angle 23.52 degrees
CCD element size 10.7 micrometer
number of elements per array 3236
Zeiss Biogon
61.1 mm
line frequency 92.978 Hz
Image Parameters
ground resolution in flight direction 2m
ground resolution cross flight 2m
length of strip 8416 lines / 16.6 km
swath width 3236 pixels / 6.4 km
swath width for triple stereoscopy 3000 pixels / 6.0 km
Table 1. Platform, sensor and image parameters for
MEOSS Dorfen strip
The computer time requirement for image matching is
about 1/2 day per baselength on modern RISC-type
workstations. It could be further reduced by streamlin-
ing of the software and - more drastically - by using
parallel computing. Both, interest operator and image
correlation tasks, can easily be distributed in terms of
different image regions to any number of CPUs.