S is expressed in
jectory and the
n stage as much
vaypoints, based
in the file. The
epending on the
data collected is
accuracy. Vital
on-line via the
configuration in
1 and distance to
The information
upplemented by
lerts or a change
ith an identifier
n the same area
are downloaded
itrol module. In
first. Typically,
t after standard
aging data for
e image library.
pass the quality
ate second stage
edure, standard
re addressed and
of the data, say
hose data which
ts will either not
ubjected to the
he basis of the
er processing is
le data. As the
sing software is
ee percentage of
means that tasks
en over by the
rary, the images
y the user. This
r to the next. In
ature extraction
ges are simply
their quality. In
ts which can be
some cases new
le the enormous
rse applications
m (DBMS) is
selection based
ometry, etc. On
; of applications
rtial automation
ble, such as the
g epipolar lines
of geometrically
tures such as
mely important.
arly stages and
will considerably add to the quality of the products to be
expected from such systems.
CONCLUSIONS
In this paper. the concept of mobile sensor systems for close-
range mapping applications has been presented with emphasis on
the common features of such systems. Imaging and navigation
hardware currently available 1s of such a quality that three-
dimensional georeferencing can be achieved with an accuracy
sufficient for many GIS tasks in urban and rural areas. In most
cases an integration of GPS, INS and an array of digital cameras
will provide the optimal solution. It offers sufficient redundancy
and the different sensors have enough complementary features to
guarantee a safe operation. Accuracy achievable today is about
20 cm (RMS) for general applications and 5 cm (RMS) for
targeted points and special operational procedures. Although the
integration concept is well understood, its implementation is bv
no means a standard procedure and requires attention to details,
such as svnchronization, data fusion, loss of sensor output, and
weighting of update measurements. Considerable work is needed
in the areas of real-time and post-mission quality control.
automation of GPS/INS integration in case of frequent lock of
loss. automatic feature extraction in post-mission processing, and
the efficient and user-oriented manipulation of extremely large
data bases. The result of solving these problems will be an
enormous extension of close-range digital mapping and its fusion
with other multi-sensor data.
ACKNOWLEDGMENTS
The VISAT system represents the combined effort of a research
team at The University of Calgary and Geofit Inc. Laval.
Quebec.
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