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4. GPS Surveying and Aerial Triangulation of the entire area
GPS surveying in this area was promoted just after the Earthquake
by Japanese association of surveyors, Association of Precise
Survey & Applied Technology and Geographical Survey Institute,
as re-establishment of Triangular Point Networks in the area.
Based on the reestablished( measured) GPS points, aerial
photos( 1000 photos) after the earthquake, were triangulated, using
analytical plotters and Albany bundle block adjustment software.
Major characteristics of this aerial triangulation ( Kobe Project ),
supported by the Ministry of Construction( Osaka National Road
Management Office) are as follows;
1) GPS Ground Controls 45 pts
2) GPS Network Adjustment
Closure of sessions( mean ) 27 sessions
dx,dy,dz 0.002m,0.002m,0.007m
0.012m,0.012m,0.016m
3) Leveling, mostly in urban area 20 mms
4) Photo Scale 1:4000,5000 - 10000
5) No. Photos 608 (1:5000),
6) Camera RC10 f = 153 mm
7) Inner Orientation < 10um, Relative Orientation < 10um
6 common sides
315 (1:10000)
8) Bundle Adjustment
Est. SDUW 0.01
Est. SDE px 0.01 py 0.01
Gplani 0.10 Galti 0.05
Adj. SDUW 0.01
Image Residuals(vx,vy)
0.0045,0.0048(mm)
Intersection Residuals(dx,dy,dz)
0.131,0.158,0.071(m)
For the pilot area ( Ashiya area)
1) GPS Ground Controls 12 pts
2) GPS Network Adjustment
Closure of sessions( mean ) 21 sessions
dx,dy,dz 0.002m,0.003m,0.004m
5 common sides — 0.008m,0.002m,0.006m
3) Leveling, mostly in urban area 20 mms
4) Photo Scale 1:4000 (Before), 1:5000 (After)
5) No. Photos (1:4000), (1:5000)
6) Camera RC10 f= 153 mm
7) Inner Orientation < 10um, Relative Orientation < 5um
8) Bundle Adjustment
Est. SDUW 0.01
Est. SDE px 0.01 py 0.01
Gplani 0.10 Galti 0.05
Adj. SDUW 0.01
Image Residuals(vx,vy)
0.0040,0.0040(mm)
Intersection Residuals(dx,dy,dz)
0.063,0.074,0.066(m)
The results of simultaneous exterior orientation are transferred as
347
CAD drawings on 3D digital terrain model of Kobe area as shown
below.
Fig. 10 Triangulated Camera positions after Aerial Triangulation
The results are converted into Database table of “ Kobe
Earthquake aerial photo retrieval system” for the future
reconstruction of the models, using either negative roll films or
existing pricked and measured films, at arbitrary time even 100
years after the earthquake.
Japan missed many chances of this type to preserve
photogrammetric records in the past major earthquakes and
disasters.
Fig 11 Faults and movements of the Ground controls
The WG has now summarized the results of bundle aerial
triangulation and movement of Ground controls in this area.
These basic point distribution expresses regional overview of the
crust movement explicitly on the existing rasterized geological
maps .
This was one of the important premises for forthcoming
3Deformation measurement, using photogrammetric models.
5. Deformation Measurements and their Presentation
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996