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EVALUATION OF DSM GENERATED FROM QUICKBIRD STEREO IMAGERY 
Shoichi Oki, Takayuki Nakamura, Mayumi Noguchi, Takahiro Shimono 
Geographical Survey Institute, JAPAN 
Kitasato-1, Tsukuba, 305-0811 Japan 
KEYWORDS: High-resolution-Satellite, Quickbird, DSM/DEM/DTM, orthorectified image, Cartography 
ABSTRACT: 
GSI (Geographical Survey Institute) is researching to apply high-resolution satellite imagery to topographical mapping. Previous 
studies with IKONOS and SPOTS show its effectiveness. QuickBird has the highest resolution among the commercial satellites. 
According to prior studies, QuickBird mono image with DEM gave good results for horizontal accuracy and discrimination. We 
confirmed the accuracy of 3D model from QuickBird stereo imagery is suitable for topographical mapping and the shift contained in 
the 3D model was decreased with a simple correction. In this study, we try to generate the digital surface model from QuickBird 
stereo images and compare the results with products from aerial photographs and aerial laser scanner. We also generate the 
orthorectified images from QuickBird images and evaluate the quality. 
1. INTRODUCTION 
The Geographical Survey Institute (GSI) is researching on the 
application of high-resolution satellite imagery to topographical 
mapping, especially for 1:25,000 topographic maps, which are 
the base maps of Japan. 
The studies of the application of IKONOS and SPOTS imagery 
for mapping were already published. They showed that 
high-resolution satellite imagery was effective for mapping 
(lida et al., 2001, lida et al., 2002, Kobayashi et al., 2002, lida 
et al, 2003). The 3D accuracy and bias compensation of 
IKONOS imagery were already studied (Fraser et al., 2002, 
Fraser et al., 2003). The evaluation of discrimination of features 
and the horizontal spatial accuracy for a QuickBird mono 
image with DEM was also published (Noguchi et al., 2003). It 
indicates the discrimination ability is good, but the image has a 
constant positional shift. Other studies of the spatial accuracy 
of the 3D model of QuickBird stereo images were also 
published (Oki et al). In the study, we evaluated the accuracy 
and tried to correct the distortion of the 3D model of QuickBird 
Stereo Imagery. The results show that a few GCP are enough 
for the correction in the purpose of topographical mapping. 
Considering the previous study on the discrimination of feature, 
QuickBird satellite imagery is effective for topographical 
mapping. 
In this study, we used stereo-pairs of QuickBird imagery of 
Yokosuka City and Tokyo, JAPAN. We generated DSM 
(Digital Surface Model) automatically from these images by 
using a digital photogrammetry software and compared them 
with DSM generated from aerial photographs and with DSM 
obtained by using an aerial laser scanner. We also generated 
orthorectified images of QuickBird images by using the DSM 
generated from QuickBird stereo imagery and evaluated them. 
2. EVALUATION Of 3D model 
In previous study, we evaluated the accuracy of the 3D model 
of QuickBird Stereo Imagery by using a stereo-pair with 60 
check points (measured by GPS) arranged densely. 
The coordinates of sixty check points measured from imagery 
(coordinates A) are compared with those of GPS survey results 
(coordinates B). Fig.1 shows the distribution of check points. 
743 
€2004DigitalGlobe. 
Fig. 1 Distribution of check points 
(Overlaid are QuickBird stereo images) 
  
2.1 Test field 
We selected Yokosuka City and its surroundings nearby Tokyo 
as a test field. It is located in a hilly district. The terrain 
elevation ranges from Om to 241m (Fig. 2). 
  
Fig. 2 Location of test field