MOBILE MAPPING FOR 3D GIS DATA ACQUISITION 
R. Li, M. A. Chapman, L. Qian, Y. Xin and C. Tao 
Department of Geomatics Engineering, The University of Calgary 
2500 University Drive, N.W., Calgary, Alberta, Canada T2N 1N4 
Telephone: (403) 220-4112, Fax: (403) 284-1980 
Email: rligacs.ucalgary.ca, WWW: http//loihi.ensu.ucalgary.ca/ 
ISPRS Com. II, WG/1 Invited Paper 
KEY WORDS: Mobile mapping, GPS/INS integration, Digital photogrammetry, GIS 
ABSTRACT: 
This paper presents technologies of mobile mapping for acquiring of large scale three dimensional GIS data based on the results 
of a cooperative research conducted at the Department of Geomatics Engineering, the University of Calgary and supported by 
Geofit Inc. and Natural Sciences and Engineering Research Council of Canada (NSERC). The mapping platform is a vehicle 
equipped with GPS, INS, CCD cameras and a computer system. With GPS providing positional data and INS providing 
orientational data, the acquired images are accurately geo-referenced. Large scale, three dimensional spatial databases can be 
constructed by extracting geometric and attribute information from these images. 
The developed prototype system combines the technologies of integrated GPS/INS, digital imaging, close-range photogrammetry, 
advanced computer graphics and object-oriented database management technologies. It is expected to have a variety of 
applications including highway mapping, city planning, automatic vehicle navigation, utility mapping, etc. 
1. INTRODUCTION 
Due to the large volume of spatial data involved in GIS 
databases, automation of data acquisition is a very important 
issue in terms of time, budget and feasibility. This is 
especially true when 3D GIS data acquisition is concerned, 
where field survey is usually carried out because map 
digitizing is often insufficient. Spatial data collection has been 
not efficient until Global Positioning System (GPS) technology 
has been applied. GPS provides a unified reference frame for 
databases. However, GPS surveying gives object positions on 
a point to point basis. To obtain 3D coordinates of an object, 
this direct measuring method requires that a GPS receiver is 
mounted on the point. Obviously this is not an efficient and 
feasible way of acquiring large volume 3D databases. An 
indirect method of data acquisition using GPS is to use GPS to 
control cameras and then to obtain 3D coordinates through 
controlled or geo-referenced images. 
The technique described in this paper is an indirect 
measurement method that combines an Inertial Navigation 
System (INS) with GPS receivers. INS can provide highly 
accurate absolute orientation data. These two systems work in 
a complimentary way. With sophisticated data processing, 
both positional and orientational data can be obtained with a 
high accuracy. Using such a configuration, the navigational 
information of the cameras is constantly updated while the 
vehicle is in motion. The images taken are, therefore, 
associated with geo-referencing data. By applying digital 
photogrammetry, any objects appearing in multiple images can 
be extracted with a reasonable 3D accuracy. 
232 
Recent developments of the system including optimal 
acquisition of 3D object coordinates, automation of feature 
extraction, object-oriented modeling, distributed computing 
architecture and animation of extracted 3D data are also 
discussed. Some results are given in the end of the paper. 
  
Figure 1: Configuration of the mobile mapping platform 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996 
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