6B-4-3
At first step, recorded image was converted to some of stereo
pair digital imageries by Video/Computer interface. As
Video/Computer interface, both image capture board (MTATCL)
and Digital Image Recorder (MR-1500) were used in order to
verify its recorder's performance on 3D-measurement accuracy.
At second step, each center position of circle (e.g. Center of
gravity) was estimated as its area gravity for each of imagery by
basic image processing procedure that illustrated on Fig. 5.
Original Image Binary Image Area Gravity
Fig. 5 Processing Procedure for Area Gravity Estimation
And each of its position of gravity on image coordinate was
calculated following equations:
where, (Uc,Vc): the Position of Area Gravity,
(Ui,Vi): Image Coordinate, Wi:Weight
At final step, the orientation of single photograph was carried
out each left and right imagery by the bundle adjustment using
mentioned 9 point's positions. And 3D-measurement was also
performed.
2) Results of Experiment
The theoretical accuracy for verification is calculated
following equations:
a xy = (H/f)o p (3)
Gz = (H/f)(H/B)ff p (4)
whwre, FI; Distance from Camera to Target(Altitude),
B; Base-Line, f; Focal Length,
a p ; Pointing Accuracy
Table 1 is the results of this 3D-measurement experiment.
Table 1 Comparison of Theoretical Accuracy
B
(mm)
Digitizing
Method
Theoretical Accuracy
a xy(mm)
a z(mm)
300
Capture Board
0.100
0.700
300
Digital Recorder
0.100
0.900
100
Capture Board
0.100
2.000
100
Digital Recorder
0.100
2.700
In the use of capture board, sufficient results were obtained.
On the other hand, Digital Recorder could not provide enough
results. One reason that we suppose is some of estimated
parameters such as scale factor were used in the inner
orientation.
The reason why no difference of accuracy was identified
depend on digitizing, is seems to be the method how center
position was estimated.
In this experiment, in order to identify the capability of sensor
integration, 3D sensor data was used as camera angles and also
executed 3D-measurement. Its results had almost same accuracy
as in the use of parameters that introduced by the internal
orientation.
Although some unsolved problems have still remained, our
development was verified to be suitable.
3. UNDERGOING AND FUTURE RESEARCH
When authors had started this research, we had already two
kinds of application plans at the same time. Next two topics are
the related research projects based on this development.
3.1 Fixed Point Observation as Total Monitoring System for
Forest Ecosystem
Fig.6 shows our system design of canopy crane in Kuba
National Park, Sarawak, Malaysia. In the end of this year, it will
be constructed. In this research project, the meteorological survey
and many kinds of ecological surveys should be done. This
system aims to realize virtual field. When this plan will be
realized, every research scientists will be able to monitor actual
field phenomena from any places through Internet.
Video Monitoring System
for Forest Ecosystem
3.1 Moving Observation as Mobil Mapping System
The authors have been repeating the experiment on mobile
mapping system. Fig.7 shows an actual experiment picture at
riverside road. This system aims to draw the map as the result of
spatial data acquisition.
Through previous experiments, every observation instruments
was identified to be sensitive for car peculiar oscillation. 3D
sensor was most sensitive especially for an azimuth direction.
Then we have been revising the system and considering the
method how we have to measure. And at the same time,
preventive mount for its damage has been designing and
developing. These mentioned preliminary experiments have
almost completed. In near future, we should start substantial
experiments using developed mount for putting all instruments
on.