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Kochi, Nobuo
1.1 Data Acquiring Part
1.1.1 Digital Camera. For the road intersection survey we used ordinary Ricoh digital camera RDC 5000 (2.3 million
total pixels. 1792 X 1200 array, 4.2 1 m/pixel, and its lens is 38mm--86mm i.e. 35mm equivalent, optical zoom). And
for the cliff side survey we used Nikon D1, which is lens-interchangeable 35mm type digital camera (2.7 million total
pixels, 2000 X 1312 array, 11.8 4 m/pixel).
Both recorded the image-data in small memory card, which can be easily processed by portable computer.
For camera calibration, we used “Self calibrating bundle adjustment software" which we had already developed (CE:
Kochi, Otani, Nakamura and others 1996).
And for RDC5000 we used 38mm and for D1, 18mm and 28mm.
1.1.2 Surveying Instrument. The image analysis requires at least 6 control points. To acquire the data we can use
Total Station or GPS. Particularly Reflectorless Total Station has the advantageous capability of measuring the object
without actually touching it and capability of supplementing necessary data afterwards.
In our system we connected Topcon Reflectorless Total Station (GPT-1002/1004) and DI-1000 to make it possible to
measure and supplement on-line.
We can use GPT series in prism mode as well as in non-prism (reflectorless) mode. In non-prism-mode we can measure
up to 100m with accuracy of = lcm.
1.2 Analyzing Part
1.2.1 Digital Image Surveyor DI-1000. DI-1000, the software we have recently developed, has the function of not
only acquiring data in the field but also of producing three-dimensional image presentations out of three-dimensional
data. When we use this function in the field to acquire and analyze data, we must first install DI-1000 in Pen-Computer.
Here DI-1000 thus installed is lined with
GPT. After the image is obtained by digital | Calibrating data Image Control points | | 3D Measurement
camera, GPT measures the strategically
imed control points and on the display of ; e
aimed control points and on the dis
P : pay o Image coordinates calculation
the Pen-Computer we touch with a pencil-
like pointed thing the same corresponding Y
points so that the orientation may be Photographic coordinates calculation
processed. The procedure is very simple. I |
Here we use DLT (Direct Linear 3
Transformation process), because it is not DLT TIN
necessary to fix the exterior orientation Orientation Interpolation
parameters. This facilitates the accurate T I
analysis of the oblique image. Sat conditions
i Irreeular Image composition
We use TIN (Triangulated gu Neston LD
Network) to interpolate the surface of three-
dimensional data so that the image of digital i
camera can be transformed to ortho-image.
Here it is also possible to automatically
compose different ortho-mosaic images.
(See: Figure 2 for DI-1000 process diagram)
Ortho-image output
Figure 2. DI-1000 Process diagram
And by using TIN we can produce various image presentations such as birds-eye-view, wire-frame, rendering, contour
line and cross-section.
If the three-dimensional features of an object can not be fully presented by the data obtained through a surveying
instrument, we make stereo-photographing, and measure three-dimensional measurement (PI-2000), and then input the
obtained data into DI-1000 to produce more accurate result.
In addition to DLT, DI-1000 has the function of relative orientation. By determining relative orientation of more than 6
control points, it can check and judge whether the obtained data can be processed through stereo-analysis or not at the
site. So, if the judgement is negative, we can immediately take photos again to avoid miscarriage and assure the
accurate and highly reliable result.
Furthermore, DI-1000 can be lined up with FC-10A (Topcon software, Digital Plain Table) on a Pen-Computer. This
enables us to add already at the site the visual image elements to two-dimensional topographical data.
And DI-1000, which thus has absorbed the data, can work off-line.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 435
