EnviSat ASAR数据在水情监测中的应用

在微波遥感领域,星载雷达是目前获取地球信息最主要的技术手段之一,而欧空局EnviSat卫星上搭载的先进合成孔径雷达ASAR是目前功能最为强大的星载雷达系统。以ASAR作为数据源,通过分析入射角、极化方式等因素对水体后向散射特性的影响,提出遥感水情监测中对ASAR数据产品的选取原则。根据水体在雷达图像数据中具有较低值的特点,使用阈值法识别水体。结果表明,使用H/H极化或V/H极化方式的数据都可以比较准确地提取水体信息。

Study on Flood Monitoring Using EnviSat ASAR Data

Remote sensing techniques have special capabilities in natural disaster monitoring.Especially,microwave remote sensing techniques could collect ground information with little impact on weather conditions relative to optical remote sensing techniques.This is useful for flood disaster monitoring.There are many instruments using microwave techniques for earth surface exploration,such as radar system,passive microwave system,etc.Until now,the ASAR(Advanced Synthetic Aperture Radar)instrument on board the EnviSat satellite is one of the most powerful radar systems.Based on the backscatter characters of water,the method for choosing appropriate products of ASAR is put forward in this paper. Generally,water has a smaller backscatter coefficient than other ground objects so it can be identified by a threshold easily.In this study,two different polarization ASAR data are used for obtaining water area information.Results indicate that the data with H/H or V/H polarization are most suitable for inundation area measurement.