ibul 2004 
Basic Study on the Preparation of Topographic Maps for Landslide Areas by an Inertial 
Photogrammetric Camera System 
Toshio KOIZUMI* Yasuyuki SHIRAI** 
Dep. Architecture and Civil Engineering, Professor Chiba Institute of Technology, Japan 
Address:2-17-1,Tsudanuma,Narashino-shi,Chiba 275-0016,J apan 
Mailing address: koizumi@pf.it-chiba.ac.jp 
**Dep. Design., Associate Professor, Chiba Institute of Technology, Japan 
Mailing address: shirai@pf.it-chiba.ac.jp 
Commission V, WG v/5 
Keywords: Landslides, Development, Measurement, Camera, Disaster, Systems, Close Range 
ABSTRACT 
With the use of an accelerometer and a gyro that are inertial sensors, it is possible to calculate both the 
distance and angle. That is, if a camera is mounted with an accelerometer and a gyro, the position and 
gradient of the camera when it takes a photograph can be calculated. In this paper, a camera mounted with 
inertial sensors is defined as an inertial photogrammetric camera. In this paper, using the inertial 
photogrammetric camera system for terrestrial photogrammetry that was developed by the authors, the 
topographic maps of landslide areas were prepared. A landslide area subject to this study was about 60 
meters in height, the width of its lower end was about 100 meters, and its oblique angle was about 50 
degrees. While moving the cart on a river bank that was located about 120 meters away from the landslide 
area, the stereo photographs of the landslide area were taken. To examine the accuracy of measured results 
obtained by the inertial photogrammetry, a white polystyrene foam plate with a size of 80 x 80 cm was 
placed on several locations in the landslide area. Those locations were then measured by a Total Station and 
the obtained data were regarded as the true values. Based on the photographs taken, a topographic map 
(contour map) was prepared. The result of the research showed that the system developed in this study was 
effective. 
1. INTRODUCTION without a control point, it would save much time 
and labor conduct the control survey and also 
Distance and angle can be calculated with a gyro would contribute greatly for simplifying the 
and an accelerometer which are inertial device. photogrammetory. Some studies that resemble 
Therefore, calculation of position and inclination of this study are introducing a system in which a 
camera become possible by installing the gyroscope camera is mounted with GPS and a gyro. In this 
and accelerometer in the camera. This study is the study, however, no GPS is used. The reason is 
fundamental research on photogrammetory usinga that the use of GPS in areas where radio waves 
camera equipped with an inertial device. If the - cannot reach is difficult. The main purpose of this 
position and the incliñation of camera which are study is to apply the system to terrestrial 
exterior orientation element are obtainable photogrammetry. In terrestrial photogrammetry,