Oyama, Yoichi 
PRACTICAL APPLICATION OF DIGITAL MAPPING TECHNOLOGY 
—CASE OF SPATIAL ANALYSIS BY 3D DIGITAL MAPPING— 
Noboru Fukushima*,Yoichi Oyama* 
* Photogrammetry Group Kokusai Kogyo Co., Ltd. Tokyo, JAPAN 
noboru_fukushima@kke.co.jp, yoichi_oyama@kkc.co.jp 
KEY WORDS: Digital Mapping, CAD, Limit Surface, Digital Photogrammetry System 
ABSTRACT 
The biggest advantage of digital mapping technology is said to be the flexibility in the expression of maps such as the 
output at optional scale and of the optional items as well as the reproduction of maps. However, these are on the 
extension line of conventional analog mapping technology and do not point to the essence of digital mapping. The real 
worth of digital mapping can be said to be the utilization of digitalized 3 dimensional coordinates. So far, attempts have 
been made to use the 3 dimensional data obtained by digital mapping for the applications of each field, and in fact, they 
have been applied to the businesses in practice. 
In this study, we discussed the method to extract the structures and topography which are protruding into the upper 
space which has to be reserved, and to identify the extent of protrusion and the locations of these objects. The digital 
mapping can be said, after all, to be the effective means to efficiently acquire the heights of scattering structures and 
topographies. 
In this paper, we will introduce the process of current study using the analytical plotter, and then report the procedures 
by which we used the digital photogrammetry system in an attempt to solve the problems found out in the process of 
current study. We will discuss the efficient study methods and new possibilities obtained from these results. 
1 OUTLINE OF THE STUDY 
1.1 Study area 
We selected a middle sized city of 40 k ni including the surrounding areas which has mountains of 200 — 300 m in 
height at its north east as the study area. 
1.2 Objects of study 
We assumed a virtual space above the study area and specified its lower limit surface. We formed the surface by 
combining a surface which has inclinations along with the ground surface and a horizontal surface. We specified as the 
study objects the tall building, towers and mountains having the value of Z coordinate which is higher than or close to 
the lower limit surface. 
1.3 Details of study 
We used monochrome aerial photograph of 1 / 20,000 for the measurement. We measured and calculated study objects 
having the highest altitude and the distance from the surface, and attempted to construct plans and longitudinal section 
maps to identify those locations. 
2 STUDY METHOD USING THE ANALYTICAL PLOTTER 
2.1 Measurement by analytical plotter (judgment whether the object is protruding over the lower limit 
surface) 
It is necessary to acquire the accurate height of object protruding over the lower limit by the actual measurement at the 
side. However, it is difficult to presume at the site whether the object concerned may contact with the virtual surface. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 1097