Honam Lee
remained conventional. Regardless of the method used, the measurement of GCPs is the weakest point in the
automation of photogrammetric orientation procedures.
2.2.1 Use of SPOT films on analytical plotter : The standard orientation programs for relative and absolute orientation
in analytical plotters are unable to process the special geometry of SPOT images. A special orientation software is
therefore required for plotting SPOT stereo models. In addition, the real-time loop of the plotter software needs to be
extended by correction grids because SPOT images do not feature central perspective.
When we used this method, it can be worked with unprocessed images, but convergence of trajectories, the difference in
scale (or resolution) along lines and the land smear effect for asymmetric view configurations make stereoscopic
viewing more difficult and tiring for operators(GDTA, 1995). One of its main characteristics is that it can be used to
plot profile or contour lines directly, and these lines are subsequently reused by the Computer Aided Drawing(CAD)
system and the output system. Finally, the digital mapping software can also include complementary measures made in
the field and can inset them in printed outputs. Figure 1 represents the schematic view of the optical system in analytical
photogrammetric station
Servocontrol
L
COMPUTER Close loop PLOTTER
A
Current postion
measurement
Operator Close MMI : nv Close Observation
commands | /oop | Menus displacements | /oop
OPERATOR
Figure 1. Diagram of an analytic plotter (O.KOLBL, 1989)
2.2.2 Use on digital plotter : These new types of instruments open up a wide range of prospects and make it possible
to work in "all digital" in order to avoid handling films. They allow the use of new tools based on specialized
processors to process information directly in digital form in complete system with DBMS and stereo plotter. (GDTA,
1995).
Digital photogrammetry is coming out from its research and development period and into day-to-day practice.
Commercial photogrammetric companies are rapidly turning to digital photogrammetric workstations and systems to
meet production requirements.
3 TEST DATA AND PHOTOGRAMMETRIC SYSTEM USED
3.1 Test Data
Once the test area were defined a detail search was undertaken. The search criteria used in this study were as the the
following priorities:
e Cloud Free
e Recent acquisition
e Differences of acquisition date
e Near vertical, left and right viewing angle
e SPOT panchromatic data only
Characteristics of these vertical viewing used in the test are summarized in Table 1.
530 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B3. Amsterdam 2000.
The
3.2
"To
gec
by
poi
Th
ver
de
of
15,
poi
3.3
Th
phi
tha
sof
3.4
in
the
me
tes