摘要
通常情况下,星载合成孔径雷达(SAR)图象上存在着不同程度的几何畸变。
这些畸变给SAR图象的应用造成了巨大的障碍。为了校正星载SAR图象的几
何畸变,使SAR图象上的数据信息和其它传感器上得到的信息进行融合,必
须对星载SAR原始图象进行地理编码,得到校正后的统一的地图坐标系上的
标准地理编码图象。为了使地理编码的过程成为一个流程,一个可以产生数据
产品的处理过程,本文在分析和研究星载SAR图象地理编码的基础上,把重
点放在建立一个实用的地理编码程序的工作上。
地理编码是星载SAR图象后处理的一个过程,它的目的在于把星载SAR
原始图象投影到指定的地图坐标系上,并校正一些几何畸变。本文从介绍星载
SAR图象的几何特性出发,分析了星载SAR图象几何畸变的特性和校正方法,
在此基础上,研究了利用卫星轨道数据和SAR成像几何进行地理编码的方法,
并使用Radarsat的SAR图象数据进行地理编码,检测了本文描述方法的效果。
在本文的后面,讨论了一种不用进行拼接的分块拟和的方法进行地理编
码。虽然它在本质上与传统的方法没有什么不同,但使用这种方法可以避免拼
接。使用一些SAR图象数据对这种方法进行检测的结果表明,这种方法可以
满足地理编码的需要。最后,本文从工程角度出发,描述了如何把产生的地理
编码的各种图象,按照某些格式写入文件,生成了SAR图象的通用处理产品。
SPACEBORNE SAR IMAGE GEOCODING RESEARCH
AND REALIZATION
Liang Wei (Information and Signal Processing)
Directed by Pro. Wu Yirong & Ding Chibiao
In general, there exist a lot of geometric distortion on satellite SAR image. In order to correct these geometric distortions on satellite SAR image, and cooperate this information on SAR image with the information from other sensors, it is necessary to geocode original SAR image, and obtain correct standard geocoded image in the defined map projection. This paper focuses on the job of building a practical program of map geocoding based on analysis of satellite SAR image.
Map geocoding is one of procedures in post-processing of satellite SAR image. Its purpose is to transfer the original SAR image to defined map reference frame by projection, and correct some geometric distortion. This paper analyzes the distortion characters of SAR image and the methods to solve these problems from SAR imaging system. On the basis of that, this paper proposes a geocoding method by using SAR image and checks the effects of that.
This paper utilizes a block-separated method to geocoding SAR image. The test with a SAR image by this way proves that it can fulfil the requirement of geocoding SAR image. At last, this paper discusses how to produce the general products of SAR image.
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