WATER BODY INFORMATION EXTRACTION FROM HIGH RESOLUTION 
AIRBORNE SAR IMAGE WITH TECHNIQUE OF IMAGING IN DIFFERENT 
DIRECTIONS AND OBJECT-ORIENTED 
XIE Chunxi 3,b ’*, ZHANG Jixian 3 , HUANG Guoman 3 , ZHAO Zheng 3 , WANG Jiao 3 ’ b 
a Chinese Academy of Surveying and Mapping,Beijing, 100039,P.R.China,wj-lover@sohu.com 
b Liaoning technical university, Fuxin, Liaoning Province, 123000,P.R.China 
Commission VII, WG VII/2 
KEY WORDS: Information Extraction, Object-Oriented, Dfferent Drections, Seckle noise , Sadow, Wter body 
ABSTRACT: 
Water resources play an important role in region planning, natural disaster, industrial and agricultural production and so on. Airborne 
SAR images provide advanced means to get water bodies information quickly and accurately because it is not affected by clouds and 
lights. Water is confused easily with shadow since calm water surface induces mirror reflection when it gives birth to echo wave. 
Hence its color is similar to shadow so that it is difficult to distinguish between water body and shadow in airborne SAR image. In 
order to achieve the goal that make distinctions between water body and shadow, the article put forward an innovation that extract 
water body information from high resolution airborne SAR image based on technique of imaging in different directions and 
object-oriented. 
1. INTRODUCTION 
Synthetic Aperture Radar(SAR) is a powerful tool for 
information extraction. However, the shadow in SAR image 
becomes the major obstacle to extract water body. In order to 
solve the problem, the article utilizes the technique of imaging 
in different directions for the same region to eliminate the effect 
of shadow. However, speckle appearing in SAR images is due 
to the coherent interference of waves reflected from many 
elementary scatters (Gianfranco de Grandi, J., 1999). Speckle 
reduction is crucial to extracting water body from SAR image. 
The article selects adaptive window Lee local statistics filter to 
reduce speckle that influence precision of water body extraction. 
At the same time in order to achieve the goal that extract water 
body and shadow, the article put forward an innovation that 
extract water body information from high resolution airborne 
used objected oriented technique, which improve the traditional 
pixel-based classification method. The outcome of 
object-oriented classification gives birth to patch that help make 
distinctions between water body and shadow. 
2. IMAGE REGISTERATION 
The method of extracting water body from SAR image demands 
that register precisely one SAR image that range direction is 
from north to south to the other that range direction is from 
south to north. The article uses geometric correction based on 
polynomial model. The other image is regard as the reference 
image to select control point. After registering two directions 
image, we cut out two sub-image of same area through image 
subset. The raw images that imaged in two directions and the 
two images used to extract is as follows: 
Figure 1. The raw image that range direction is from north to 
south 
Figure 2. The raw image that range direction is from south to 
north