The Intel national Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
95
GPS Shift/Drift Correction and INS Shift/Drift Correction
check box(See Figure 2), then Click Ok, press Compute to do
block adjustment, and, as desired, monitor the progress of the
computation in the Solution Progress dialog box. If there is
antenna height correction, we will also select Antenna Offsets,
and input X, Y, Z correction parameters.
Adjustment Mode
r g elative
; (• Absolute
Adjustment Parameters
[✓ Enable Precision Computation
f~ Enable Error Detection
P Chiude Manual
\ r~ On tdr I
JSl
Camera Calibration Settings
f* Camera Catenation [
Given EO / GPS / INS Settings
p EnableÉivenEO/GPS
Antenna Offsets
p GPS Shift/Drift Correction
p INS Shift/Drift Correctiorl
Residual Filter Options
f~ Auto Threshold
f~ 2D {mage Pont Residuals
r~ X> Qbiect Point Residuals.
Display Precision Settings
Image Decimal Precision fT
Object Decimal Precision: |3
Point Fier Options
& Tie Points
Î7 Pass Points
P Control / Check Pomts
Number erf Rays Fiter:
Min: |0 Metcliw“
U.inSWD*
r p OOT
CacnMaID I On 1 FociLength . [Ön I PPACXSldD, [pPACYSId .. 1
597029042 011 0.030 nmo nn„.
r Sell - Calbtetion j~
r. r
r r
r 5 ri
r r .
I Enabled Additional Paramele««
N
Camera ID
1 X Offset
1 Y onset
1 Z onset
597029042
0.000
0.000
0.000
Figure 2
orientation on the models, by block ID, or by model ID. Click
Compute, and review the results when they are displayed.
Finally, we use Export command in Translators menu to export
PATB > EO and Control reports.
p Photo Statistics
p Object Statistics
p Point Statistics
p Exterior Orientation
p GPS Statistics
p INS Statistics
T iSelf-Caiibration Statistics!
Help
Cancel
Figure 3
4. CONCLUSION
Through the aerotriangulation of Spanish project, we are more
skillful with ISAT sofware. We think it has good reliability,
quality and function. It can work for large projects more
conveniently and effectively. Its points matching can reduce a
lot of manual points selection work. With GPS\INS aid, we need
less ground control points, so the field work has been reduced a
lot too. Furthermore, DMC images do not need to be scanned, it
also increase the efficiency of aerotriangulation.
When computation completes, we can analyze the triangulation
results, view the summary statistics to check whether the
solution is satisfactory or not. Check sigma value, Root Mean
Squares(RMS) errors of control and check points, maximum
control point residuals, and mean standard deviation values of
the object point coordinates and EO parameters, and check if
the drift value between exterior orientation and input GPS\INS
is within accuracy. If there are still big residual error ground
control points, we can written down the point label and use
Point Measurement command(ISAT menu) or Multiphoto
command(Orientations menu) to re-measure the points in stereo.
After we adjust the ground control points, we can re-do bundle
adjustment till the result reaches the accuracy requirement. This
step will Commit the bundle adjustment results to the project
files by clicking OK on the Photo Triangulation Results dialog
box. This writes the computed EO parameters to the Photo file
and the adjusted tie/pass points coordinates to the project Triang
file. The absolute orientation accuracy for this project is Max
Rms X,Y^0.1m; Z^O.lm.
3.8 Submission of final result
After the relative orientation and absolute orientation meet the
accuracy requirement, we can click Reports in Photo
Triangulation Results dialog box, a PhotoT Reports will come
out, See Figure 3. The computed EO parameters has been
written into Photo file when we do block adjustment; Select the
Densify command(Orientations menu, Photo Triangulation
submenu) to open the Densification dialog box, click OK to
densify control procedure and this process writes the calculated
ground coordinates of the tie/pass points from the Triang file to
the Control file. Select the Bulk Orientation command
(Orientations menu, Photo Triangulation submenu) to open the
Bulk Orientation dialog box. At a minimum, select the Relative
Orientation and Absolute Orientation check boxes. Select
photos and models to perform relative orientation and absolute
In high-speed developing information society, satellite
navigation system has been widely used and it can provide high
precision service. GPS has the function of navigation,
positioning, timing, and measuring etc. Besides, with the
development of aerophotography technology, there will be more
and more DMC digital images with air-borne GPS and INS
which can takes place of aerophotograph films and scanners.
We believe ISAT will be used more and more widely.
REFERENCES
Chen Xiaoming, 1992. Theory and Application of High
Precision GPS Dynamic Positioning:[Doctoral Thesis]. Wuhan:
Wuhan Science and Technology University of Surveying and
Mapping, 1997
Li Deren, Zheng Zhaobao. Analytical Photogrammetry.
Beijing: Surveying Publishing House,
Users’ Manual of ISAT
Wang Huinan. 2003. Principle and Applications of GPS
Navigation..Beijing:Science Publishing House
Yuan Xiuxiao, 2001. Theory and Application of
Aerotriangulation with GPS Aid. Beijing: Surveying Publishing
House
ACKNOWLEDGEMENTS
During writing this paper, Mr. Bai Zhigang gave us the
constructive support, and Ms.Peilei made the translation for this
article. Here we would like to express our hearfelt appreciation
to them.
