LARGE SCALE GEOGRAPHIC INFORMATION ACQUISITION BY 35mm CAMERA
Joon-Mook Kang
Dept. of Civil Engineering, Chungnam National University
Taejeon, 305-764, Seoul, Korea
Won-Jin Oh
Dept. of Cadastral, College of Chungcheong
Cheongjoo, 363-890, Seoul, Korea
Yeon-Soung Bae
Dept. of Civil Engineering, College of Chungcheong
Cheongjoo, 363-890, Seoul, Korea
Commission V, WG 4
KEY WORDS : NON-METRIC, CAMERA, PHOTOGRAPHY, AERIAL, BUNDLE, GPS, DIGITAL, MAPPING
ABSTRACT
In this study, we try to develop the technique for acquiring the geographic information of large scale at small area efficiently.
Above all, so as to indicate the fiducial mark in the non-metric camera, we mounted the glass plate after manufacturing it and
extracted the lens distortion coefficients by calibrating the wide-angle lens of which the focal length is 35mm. We loaded the
developed semi-metric camera and manufactured the radio control airplane which is suitable for the aerial photography.
We could secure the stablility of control and photography of airplane through diverse flight experiments. And, we analyzed
the accuracy by taking the aerial photography with diveres photography altitude and endlap about ground target. As the result,
it could be seen that the limit of photography altitude to be able to obtain the topography information with the demanding
accuracy is 400m. For the saving of time and expense at the time of measuring the ground control points, we decided the
ground control point(GCP) coordinates by using GPS static and kinematic mode.
In addition, by using the built photogrphy system, we photographed 28 sheets of aerial photoes of 3 strip in consideration
of demanding accuracy on the area that the real route design is demanded, and made out the digital map by analytical plotter.
We could suggest the efficient and economical acquisition method of geographic information of large scale by calculating the
profile, cross-section and earthwork volume about the route aligment of newly established road from the obtained digital terrain
model(DTM).
1. INTRODUCTION
Recently, much interest is concentrated on the
manufacture of digital topographical map which has various
merits by getting out of existing topographical map on the
basis of the sudden development of the computer and the
image processing technique. Especially, digital terrain model
(DTM) as the basic drawing for the establishment of GIS is
the data form to be required indispensably. So, it is
forecast that it will be applied very widely over the whole of
Civil engineering field. Now in our country, we are acquiring
the geographic information at the large area which is
necessary for the framing of basic drawing of country, the
management of country, the management of environment,
the military special goal, the investigation of resource and
the topography analysis etc. through the photograph taken
by airplane or image taken by satellite(Kang,1993). However,
it is the real situation that the method to acquire the
geographic information which uses satellite image or aerial
photo or topographical map is being used by being limited
to the extraction of geographic information of small scale for
the most part. And in case of aerial photo, it is difficult to
take a photo except the big business of national project and
development, the place for the take-off and landing of
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airplane is being limited extremely. Therefore, the geographic
information of large scale which is demanded at the time of
development of small area or at the time of execution route
design is depending on the conventional method to invest
vast manpower expense and time.
Thus, it is the real situation that the framing of profile
and cross-section for route design and the succeeding work
such as the calculation of earthwork volume as well as the
acquisition of topographical information cannot help
depending on the conventional manual work.
So the development of technique for acquiring the
geographic information of large scale with digital data is
being required keenly for the improvement of construction
technique of our country.
Thus in this study, we performed the basic study about
making the non-metric camera of 35mm into the use for
measurement, the establishment of photography system by
. the small-size airplane of radio-control(R/C), the analysis of
measurement accuracy of aerial photo measurement by this
system and the efficiency of introduction of GPS technique
to the measurement of GCPs. And we try to suggest the
efficient acquisition method of geographic information of
large scale by 35mm camera by applying this system to the
real design of small route.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996