ng this
"he test
amera.
aneous
linates
üch is
m the
ection
Jeyapalan, Kandiah
Calibration of Mandli CCD Camera Using Test Range
Std Dev of Residuals Calibrated Principal Standard Error
At Control Points (ft) Distance of unit weight
X Y Z (pixel)
Photo 1 0.268 0.301 0.041 -165 5.09E-01
Photo 2 0.689 0.508 0.088 -878 2.33E+03
Photo 3 0.057 0.120 0.025 -868 4.61E+00
All Photo 0.438 0.315 1.531 -774 2.77E+04
Table 3. Results of Calibration
Table 3 also shows that (X,Y,Z) of feature locations using the multiple video imageries (non stereo) can be obtained to
an accuracy less than +0.5 ft; however the accuracy in Z is about +1.5 ft. The error of +0.5 ft in (X,Y) is acceptable for
mapping at a scale of 1"=25' or smaller. The error of +1.5 in Z is acceptable for information about road side features
but not for preliminary or location surveys, which may require + 0.1 ft accuracy.
Table 3 also suggests that the strict photogrammetric model used in the Calib may not be acceptable for calibrating a
digital imagery. However, by limiting the object distances from 25 to 50 ft from the camera and the camera locations
from 0 to 15 ft, it may be possible to get accuracies better than + 0.5 ft in all (X,Y,Z).
Fig 12 shows a video logging system of Transmap which is equipped with a pair of digital cameras unlike the Mandli's
system which used only one camera. Four pairs of the Transmap's video imageries , 25 ft apart (See figure 13), and the
soft plotter, which is a soft photogrammetric workstation by Autometrics Inc, were used to produce the GIS map
showing the roadside features. First, the digital cameras were calibrated using the Calib software. Then, using the
interior orientation elements, a triangulation was done using the soft plotter, followed by collecting line and point data,
viewing one stereo pair at a time on the stereo plotter. See fig 14.
The Fig 13 shows that the location of features between stereo pairs are satisfactory. However, locations of features
obtained beyond 50 ft from the camera are not acceptable for mapping at a scale of 1" —25' scale.
Fig 12. TransMap Van Fig 13. TransMap Video Image
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 411