1. Aerial Photography in Kobe Earthquake
and Organizing a WG( Digital Photogrammetry)
Kobe Earthquake attacked the Awaji Island , Akashi bridge under
construction and densely populated area; Kobe city, Ashiya city,
Nishinomiya city ,amagasaki city and Osaka city in Japan widely
and severely at 5:46 a.m. on Jan. 17 1995.
Many photogrammetrists worked for rescuing, investigating and
reconstructing the damaged area just after the first news from
mass communication media.
Flight crew started to take aerial photos of the damaged area
through the dust and smoke , with overlapped scenes and oblique
shots, over and over ,for several days, at large and small photo
scales (from 1/1,300 to 1/25,000).
Table 1 shows a list of aerial photos taken by 10 organizations just
after the earthquake, over the entire area.
Organization|Period | Photo No. |No. Covered
(95) |Scale Str.|Photos |Area
Air Graph 117 |1:10000 2 109 |Urban area
Asahi Koyo .|1/17- |1:5000- 37| 1710 [Kobe
1/21 |1:10000 Rokko Mt.
Asia 1/17- |1:4000- |160| 4979 |Kobe
2/11 |1:20000 Rokko Mt.
G.S.l. 1/17- |1:7000- 89| 3571 |Awajils.
2/1 |1:20000 Kobe,
Hasshu 1/18- |1:8000- 26 664 |Urban area
1/24 |1:14000
Kanko 1/17- |1:4000- 13 900 |Urban area
2/19 11:15000
Kokusai 1/17- |1:4000- 48| 1678 |Kobe
1/24 11:20000 Port Is.
Nakanihon |1/17- |1:4000- 37| 1183 [Urban area
1/24 1:20000
PASCO 1/18- |1:1300- |122| 4178 |Awaijils.
2/28 |1:10000 Kobe, Osaka
Toa 1/28 |1:25000 2 36 |Kansai Airpo
Tab.1 Aerial Photos after the earthquake
Working group (Deformation Analysis of the Kobe Earthquake
using Digital Photogrammetry) ,in Kobe Earthquake Investigation
Commission of Japanese Geotechnical Society ,was organized
and guided by Dr. Okamoto a week after the earthquake.
Members collected copies of flight line maps of the whole
organizations , and started to digitize them into CAD system.
Parallel with photo mosaicking, the authors planed to produce
digital orthophotos out of these aerial photos for initial investigations
among geotechnical researchers .
The WG organized the investigation projects as follows;
1) GPS surveying and aerial triangulation of the entire area
(10km x50km, from Kobe city to Osaka City)
2) 3D deformation measurement using aerial photos with analytical
and digital plotters for pilot areas
3) New configuration of aerial photography, based on GPS
navigation system and digital map data, including raster
maps, such as geological maps
4) 3D presentation of the investigated results on 3D digital terrain
models and texture maps, including 3D animation
Aerial photos in print were sold widely to the municipal,
governmental and private companies, such as general construction,
real estate and insurance companies from individual aerial survey
companies, for getting approximate regional overview.
GPS navigation system for aerial flight was under testing at the
period of earthquake, most of the flights were accomplished in the
ordinary (experimental) way and aerial flight line maps as well.
Aerial flight line maps were made on existing 1/25000,1/50000
topographical maps, and copied for delivery to the common users.
This process has been modified in such a way that a GPS receiver
on an aircraft takes exposure positions and transfer them directly to
the PC for CAD system, combined with raster (image) map data.
Leica ASCOT system and Kyoritu VEGA system were used in a
testing-modification process after the earthquake.
Most of color prints were used as albums for reference and simple
color copies were the most popular media in practice, and even
photo color mosaics were used for exhibitions and explanatory
meetings mostly, then real productive tools in the future might be
digital color mosaics( orthophotos) or satellite image
data ,immediately acquired after a disaster.
We continue to propose the entire procedures(manuals) for aerial
photography for many kinds of disasters.
With respect to this matter, we have tested the following items;
1) rasterized maps; scanning, editing and printing for CD format
2) superimposition of vector maps on raster maps, orthophoto
images within CAD environment
3) Orthophoto production from negative roll films to paper prints
4) Pen computers of A4 or A5 size used at site consistently
Our experience and investigation taught us some considerations .
Consideration Item |at the Earthquake |in the future
Flight budget voluntary flight reserved fund
command system [flight office emergency manual
flight planing paper map GPS flight design
(aerial triangulation ,
digital ortho oriented
flight management |pilot, navigator GPS navigation
,cameraman system
film development |separated process — |combined process
duplication
high precision
measuring material
individual storage
(depository)
3 major materials
database
ground controls GPS surveying under |continuous GPS
testing network Sa
digital orthoimage [simple color print in production
project plan individual public organization
Tab.2 Aerial photography in future
344
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
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