ul 2004 
RED 
the data 
rd (ISO / 
2-1. 
   
    
   
  
le on or 
surface or 
, lighting 
consisting 
surface 
sidewalk, 
stalled to 
tures and 
  
nel 
a 
attribute 
relation 
uipment, 
2-2, there 
pole, and 
out such 
  
und 
igure 2- 
t 
a 
se of the 
ilk, edge 
International Archives of the Photogrammetry, Remote Sensing and 
Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004 
  
of road shoulder, etc.) which consists of the road surface having 
the area 
(2) 70 em or less (accuracy at the level of 1 / 1,000) in case of 
the facilities (telephone pole, manhole, etc.) located on the road 
The accuracy at the level of 1 / 500 or 1 / 1,000 means the value 
specified in Public Survey Work Regulation of the Ministry of 
Land, Infrastructure and Transport.. 
3. REQUIREMENTS OF DEVELOPMENT 
The conditions precedent and requirements for the development 
of mobile mapping technology are as follows. 
3.1 Condition precedent 
(1) Study area 
The study area is the road area. There are high bridge and 
multi-level crossing over a part of road, and these portions are 
concealed in the aerial photograph taken from the above. 
Therefore, it is necessary to acquire the data of these parts. 
(2) Speed of vehicles 
In the general national road, the vehicles are not allowed to stop 
on the car lane excepting at the time of stop signal at the 
crossing of congestion of traffic. As a result, measurement is 
made while the vehicle is traveling, and therefore, the photo 
shooting distance will vary according to the speed of vehicle if 
the shutter interval is fixed. 
3.2 Requirements of system development 
(1) Scope to be measured 
The spatial data to be measured are located at every direction as 
shown in Figure 3-1, and therefore, all of these information 
must be measured. 
  
    
    
   
  
the head 
Signal pole 2 
Road information board © 
    
Ground structure at 
the side direction 
Manhole 
A us - 
Bas... d 
Ground structure at frontward Road sign 
Road surface indicator Protective fence, etc 
  
  
  
Figure 3-1: Scope of measurement and spatial data to be 
measured 
(2) Maintenance of measuring accuracy 
As stated in Section 2.3, the measuring accuracy is as follows. 
1) 25 cm or less in case of the border line having the area such 
as the edge of road or sidewalk and the edge of road shoulder 
2) 70 cm or less in case of the ground structure on the road such 
as telephone pole, manhole and toad sign 
69 
The accuracy will not be uniform but vary according to the type 
of ground structure. 
(3) Necessity to measure the attributes of ground structures and 
relation information 
As stated in Section 2.2, it is necessary to acquire thematic 
attributes and relation information of the spatial data. 
For example, the acquisition of classification or code number is 
specified by regulations for the guide board and road sign that 
indicate the destination, and therefore, the measuring method 
must be able to identify these numbers. Also, as for the 
acquisition of relation information, it is required to identify the 
ground structured added to the pole (sign, signal, etc.). 
(4) Must be compatible with photographic survey and ground 
survey 
We do not expect that all the spatial data will be completed by 
the mobile mapping technology. Cooperation is necessary with 
other measuring methods in order for the efficient measurement, 
and therefore, it is necessary to have compatibility with the data 
acquired by other methods. 
  
   
Aerial photograph survey 
  
    
    
   
Mobile 
mapping 
  
  
  
Figure 3-2: System of spatial data generation 
4. DISCUSSION ON THE SYSTEM CONFIGURATION 
The basis of the mobile mapping system to be developed is to 
calculate the correct position and- posture of platform 
(automobile) using GPS / IMU technology and acquire the 
spatial data of ground structures located at roadside (attribute 
information such as position, type, shape, etc.) by non-contact 
type measuring sensor mounted on the platform. 
4.1 Discussion on the system configuration 
In discussing the system configuration, we must select the 
objects measuring sensor and position self measuring sensor to 
be mounted on the platform. We also discuss the method to 
synchronize each sensor and the measuring vehicle which is 
used as the platform, as well as their installation method. 
(1) Selection of objects measuring sensor 
In a rough classification, there are area sensor and line sensor as 
the method of non-contact measurement of the ground 
structures on the roadside. The characteristics of these sensor 
are shown in Table 4-1. As the condition for selection, it is 
pointed out that the sensor should have enough spatial 
resolution to identify the detailed characteristics of ground 
structures. The digital video sensors are excluded because their 
spatial resolution of image is insufficient.