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A METHOD TO DETERMINE SPATIAL RESOLUTION OF REMOTE SENSING FUSED 
IMAGE QUANTITATIVELY 
X.J. Yue *• b , L. Yan b , G.M. Huang a 
a Chinese Academy of Survey and Mapping, 16 Beitaiping Road, Beijing-(xijuanyue, huang.guoman) @163.com 
b School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan-lyan@sgg.whu.edu.cn 
KEY WORDS: Spatial Resolution, Remote Sensing Fused Image, Correlation Coefficient, Bias Index, Image Aggregation, 
Determine Quantitatively 
ABSTRACT: 
Spatial resolution of remote sensing fused image is usually the spatial resolution of high spatial resolution image which is not the 
real spatial resolution of the fused image. A method of determining spatial resolution of remote sensing fused image quantitatively is 
presented in this paper, based on correlation coefficients and bias indexes between different spatial resolution image aggregation 
which resolution is 11m, 12m, till 20m obtained by the resample of SPOT pan image which resolution is 10m and fused images 
obtained by the fusion methods of HIS, PCA, and Brovey. The experiments have been done on the fused image from SPOT pan 
image(lOm) and TM multi-spectral image(30m), and the spatial resolution of the fused image is closer to 17m. 
1. INTRODUCTIONS 
In the recent years, remote sensing image fusing is one of hot 
points of research in home and overseas. With the appearance 
of kinds of fused methods, remote sensing image fusing 
technology is developed fast. All of the purpose of the methods 
is to keep spectrum information and enhance spatial 
resolution[Liu CH.P., 2002]. Spatial resolution is one of the 
criterions of evaluating image quality, and which is also an 
important parameter in image application[Hao P.W., 1998]. 
In the preprocess course of remote sensing image fusing, bad 
accuracy of geometric-rectification and image matching will 
decrease the spatial resolution of remote sensing fused 
image[Yang J., 2003], which is also effected by different 
methods. Considering frequency field[Hao P.W. et al, 1999], 
high frequency of pan image will be lost in the fused course, 
which will also cause resolution decrease. Spatial resolution of 
remote sensing fused image mentioned is generally the 
resolution of the pan image which is not the real resolution. 
How to determine quantitatively the real resolution of remote 
sensing fused image is one of the different problems in the 
remote sensing image process field at all times and there is no 
uniform method to resolve now[Ji T.K. et al, 2005]. 
Through constituting image aggregation of different spatial 
resolution and comparing the correlation coefficient and bias 
index between different spatial resolution image aggregation 
and fused image, the real resolution of remote sensing fused 
image is determined quantitatively in this paper. 
2. EXPERIMENT DATA 
Figure 1 is a SPOT pan image which resolution is 10 meter(m), 
and Figure 2 is a TM multi-spectral image which resolution is 
30 meter(m). The two images are the same area, which have 
been geometric-rectified and matched. Figure 3 is the 
information of the images. 
Figure 1. SPOT image Figure 2. TM image 
3. EXPERIMENT METHOD 
3.1 Constituting Image Aggregation of Different Spatial 
Resolution 
The images which resolution are 11m, 12m, till 20m are 
obtained through the resample of SPOT pan image. The 
resolution of the fused image is high than 20 m. Figure 4 is the 
image aggregation. 
* About the auother: YUE Xi-juan(1981-), female. Ph.D. Her main research interest is remote sensing image processing. 
E-mail: xijuanyue@163.com