The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
a T X u a = 1 
b T X 22 b = 1 
Cor{U,V}= a T I 12 b = max 
In fact, the problem can be described as solving the values 
a and b that can make a T X )2 b be maximum under the 
condition of a T X,, a -1 and b T X 22 b = 1 , which may use 
Lagrang solution. After a and b are solved, two group of 
random variables are transformed so as to obtain the detection 
results from the difference vectors. 
3.2 Classification and attribute information acquisition 
After the prior information is obtained from land use database, 
the attributes of the change polygon is acquired by the 
supervised classification of image. Classification is done by the 
supervised classification based on fuzzy subordinate level 
(Wang Jian et al, 2006). Firstly, the land use information of the 
detected region is gotten from the land use database. Then, the 
image can be classified according to the information of land use 
categories and the prior spectral information. At last, the 
polygon attributes may be achieved from the database. 
The fuzzy subordinate level function of the classification is 
determined by Bayesian formula. That is: 
„«(,)- /w**i«*> «> 
£/>(<»,№ I ® y > 
Where, P(co.) and P(X | co i ) respectively represents the prior 
probability and conditional probability of the category (O i . In 
the case of normal distribution, the conditional probability is 
determined by following formula: 
P(X\co i ) = 
(2*) ,/2 lX,| ,/2 * 
(7) 
Where, V. andX / respectively represents the fuzzy mean value 
vector and fuzzy variance matrix of the different category. 
The fuzzy subordinate levels of the initial sample pixels are 
given according to experience and statistical analysis results, 
and make up of the matrix called fuzzy matrix. If the number of 
samples is n, and the amount of samples pixel is m, then the 
fuzzy segmentation matrix can be expressed as: 
/*,(*,) 
Mi (X 2 ) ., 
•• mAXJ 
Mi&x) 
■■ Mi(X m ) 
mA*2) ■ 
mAxj, 
Where, ^ (x. ) is the subordinate degree of the pixel x t0 the 
category i. 
All kinds of the fuzzy mean vectors and fuzzy covariance 
matrixes can be obtained according to the fuzzy segmentation 
matrix. Each pixel is ultimately classified by its subordinate 
degree through the iterative calculation. On the one hand, the 
polygons edges are vectorized to update the vector information 
of the land use database, on the other hand, the attribute 
information is achieved from the land use prior information. 
4. PLOYGON DETECTION AND ATTRIBUTE 
INFORMATION ACQUISITION 
The system may implement the land use database updating 
based on the orthoimages captivated at a different time, as well 
as the polygon print, and the report forms of the attribute 
information output. The primary operation flowline is shown in 
Figure 2. 
Figure 2. Operation flowline of the dynamic monitoring for land use