ORIENTATION OF MOMS-02/D2 AND MOMS-2P IMAGERY
H. Ebner, T. Ohlhof, E. Putz
Chair for Photogrammetry and Remote Sensing
Technical University Munich, D-80290 Munich, Germany
Phone: +49-89-2892 2671, Fax: +49-89-280 95 73
E-Mail: timm@photo.verm.tu-muenchen.de
Commision III, Working Group 1
KEY WORDS: Orientation, Three-Line, CCD, Bundle Block Adjustment, MOMS
ABSTRACT
This paper deals with the orientation of 3-line imagery which has been taken during the MOMS-02/D2 experiment in
spring 1993, and which will be acquired in course of the MOMS-02/PRIRODA project, scheduled for launch in April
1996. The reconstruction of the image orientation is based on a combined adjustment of the complete image, ground
control, orbit and attitude information. To this end, the conventional bundle adjustment algorithm is supplemented by
a rigorous dynamical modeling of the spacecraft motion to take orbital constraints into account.
The results of the combined adjustment using MOMS-02/D2 imagery and control information of orbit #75B are pre-
sented. About 14 000 conjugate points in one imaging sequence covering 430 x 37 km? were processed together with the
epoch state vector, attitude data and 12 GPS-derived ground control points (GCP). Within the threefold overlapping
area an empirical accuracy of 12m (0.9 pixel) in planimetry and 7m (0.5 pixel) in height was achieved as verified by 63
independent check points.
Computer simulations on MOMS-2P image orientation and point determination based on realistic input information
have shown that the accuracies of the estimated exterior orientation parameters and object point coordinates will be in-
sufficient, if single strips are processed without any ground control, due to the poor absolute attitude information. Good
accuracies, in constrast, can be obtained either with a few precise GCP or even without ground control information, if
a block of several overlapping strips with high geometric strength (g = 60%) is adjusted.
1 INTRODUCTION
During the 974 German spacelab mission D2, success-
fully flown in April/May 1993, the Modular Optoelectronic
Multispectral Stereo Scanner MOMS-02 acquired digital
high resolution, along track, threefold stereoscopic and
multispectral imagery of the earth surface. The MOMS-
02/D2 experiment was the first use of a 3-line camera
in space. Although the results of this experiment are
remarkable, the high accuracy potential of the MOMS-
02 sensor couldn't be exhausted due to several prob-
lems. These problems, however, have been an important
experience in the preparation phase of the forthcoming
MOMS-02/PRIRODA (MOMS-2P) mission from the Rus-
sian space station MIR, scheduled for April 1996.
The photogrammetric processing of the MOMS-02/D2 and
MOMS-2P data is conducted by several German university
institutes and the German Aerospace Research Establish-
ment (DLR). The major aim is to realize the entire pho-
togrammetric processing chain, which starts with radio-
metrically corrected image data and ends up with digital
terrain models (DTM), orthoimage maps and vector data
for geoinformation systems (GIS). Within the science team
the Chair for Photogrammetry and Remote Sensing of the
Technical University Munich (TUM) is responsible for the
reconstruction of the exterior orientation by combined ad-
justment and the semi-automatic extraction of linear ob-
jects for updating the German GIS ATKIS-DLM25.
After a description of the two camera experiments MOMS-
158
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B3. Vienna 1996
02/D2 and MOMS-2P and the combined block adjustment
concept, the results of the adjustment using MOMS-02/D2
imagery of orbit #75B are presented and assessed. Then
the results of computer simulations on MOMS-2P image
orientation are discussed. Finally the experiences are sum-
marized and an outlook is given.
2 MOMS-02/D2 AND MOMS-2P CAMERA
EXPERIMENTS
2.1 MOMS-02/D2 Experiment
The optical system of MOMS-02 consists of a stereo mod-
ule and a multispectral module (Figure 1). In 7 different
imaging modes certain combinations of the panchromatic
stereo and the multispectral channels can be selected. The
3 lenses of the stereo module with 1 CCD sensor array
(Fairchild 191) each provide 3-fold along track stereo scan-
ning with different ground resolutions. The nadir looking
CCD array (4.5 m ground pixel size) comprises 2 arrays
with 6000 sensor elements each, which are optically com-
bined to 1 array with 9000 sensor elements. The other
CCD arrays of the stereo module consist of 6000 sensor el-
ements (13.5 m ground pixel size). In stereo imaging mode
1 8304 sensor elements of the HR channel and 2976 sensor
elements of the stereo channels are active.
In the course of the 10 day lasting D2 mission, 48 data
takes with a data volume of 300 GB were recorded during
4.5 h, covering an area of about 7 Mio. km?. Due to the
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