02/D2 experiment in
d for launch in April
nplete image, ground
n is supplemented by
| orbit. 4275B are pre-
sed together with the
threefold overlapping
eved as verified by 63
tic input information
oordinates will be in-
de information. Good
ontrol information, if
ned block adjustment
t using MOMS-02/D2
d and assessed. Then
on MOMS-2P image
? experiences are sum-
AS-2P CAMERA
NTS
t
1sists of a stereo mod-
sure 1). In 7 different
5 of the panchromatic
s can be selected. The
1 CCD sensor array
long track stereo scan-
ns. The nadir looking
e) comprises 2 arrays
ich are optically com-
elements. The other
nsist of 6000 sensor el-
n stereo imaging mode
annel and 2976 sensor
active.
. D2 mission, 48 data
|» were recorded during
Mio. km?. Due to the
i countries in Europe
na 1996
MOMS-02/D2 | MOMS-2P =
Camera carrier
Mission duration
Data storage
Space shuttle
10 days 18 months
HDT recorder onboard mass memory and
MIR space station
telemetry to ground stations
Orbital height [km] 296 400
Orbital inclination [?] 28.5 51.6
Ground pixel size nadir/stereo [m] 4.5 / 13.5 6.0 / 18.0
Swath width nadir/stereo [km] 37 / 78 50 / 105
Geometric camera calibration laboratory laboratory, inflight
Orbit information TDRSS tracking GPS
Attitude information IMU IMU, star sensor
'Table 1: Main parameters of MOMS-02/D2 and MOMS-2P
Figure 1: Optical system of the MOMS-02 camera. The
two inclined (+21.9°) stereo lenses are depicted in the
background. In the foreground, the high resolution lens
is visible, arranged between 2 lenses for multispectral data
recording.
and North America have not been imaged. More detailed
information about the MOMS-02/D2 camera experiment
is given by Ackermann et al. (1989), Seige and Meissner
(1993) and Fritsch (1995).
'To demonstrate the combined adjustment of MOMS-02
imagery using orbital constraints, one imaging sequence
with 32120 rows covering 430x37 km? in North-West Aus-
tralia (orbit #75B) has been chosen (see section 4).
2.2 MOMS-2P Experiment
The MOMS-2P camera is part of the PRIRODA module,
which is equipped with several remote sensing instruments.
Overall goals of the PRIRODA (russ. nature) project are
to investigate nature processes and to further develop re-
mote sensing methods (Armand, Tishchenko 1995).
The main parameters of the MOMS-2P experiment are
listet in Table 1. In contrast to the D2 mission, the MIR
orbital inclination of 51.6° also allows for imaging of in-
dustrial countries in Europe and North America. Since
MOMS-2P images, acquired during 18 months mission
duration, will enable a regional covering, a simultaneous
block adjustment of several overlapping strips will be pos-
sible.
The camera geometry including the alignment of the
MOMS-2P camera axes will be determined not only by cal-
ibration in the laboratory, but also by inflight calibration
using precise ground control in Catalonia (Iberian Penin-
sula)(Kornus et al. 1996).
A special navigation package MOMSNAV consisting of
high precision GPS and Inertial Measurement Unit (IMU)
ensures precise orbit and attitude data, synchronized with
the MOMS-2P imagery to 0.1 msec. Based on GPS ob-
servations during a time interval of ca. 5 minutes and a
sophisticated short arc modelling, the MIR orbit will be
determined with 5m absolute accuracy. The Astrol star
sensor, which is mounted on the QUANT module of the
MIR station provides 10" attitude accuracy, the aligne-
ment, however, between the QUANT and the PRIRODA
module will be known only in the order of 200".
3 COMBINED BLOCK ADJUSTMENT
The photogrammetric point determination is based on the
principle of bundle adjustment and comprises the deter-
mination of object points and the reconstruction of the
exterior orientation of the 3-line images. It represents a
central task within the photogrammetric processing chain
on which all subsequent products are based.
The collinearity equations
u = u(x,2*(t),0() (1)
formulate the relationship between the observed image co-
ordinates u — (u5, uy)", the unknown object point coor-
dinates 2 —(X,Y, Z)? of a point P and the unknown pa-
rameters of exterior orientation 2* = (X*,Y*, Z-)T and
p (6, m, 6)”; respectively, of the image I; taken at time
t. The orientation angles (,n and 4 have to be chosen in
such a way that singularities are avoided. In space pho-
togrammetry the three Euler angles, which are related to
the spacecraft motion along the trajectory, are well suited
in conjunction with a geocentric object coordinate system.
3.1 Conventional Approach
In general, the mathematical model for the reconstruction
of the exterior orientation should use 6 unknown parame-
ters for each 3-line image I;. In practice, however, there is
not enough information to determine such a large number
159
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B3. Vienna 1996
