Detection of flooded urban areas in high resolution Synthetic Aperture Radar images using double scattering
Detection of flooded urban areas in high resolution Synthetic Aperture Radar images using double scattering
复制标题
DOI：
10.1016/j.jag.2013.12.002
复制
发表时间：
2014-05-01
影响因子：
7.5
通讯作者：
Cloke, H. L.
中科院分区：
文献类型：
--
作者：
Mason, D. C.;Giustarini, L.;Cloke, H. L.
洪水是世界各地城市地区的一种特殊危害，因为这些地区的生命和财产风险增加。合成孔径雷达（SAR）传感器由于其全天候的能力，经常被用于图像洪水，现在拥有足够的分辨率图像城市洪水。从图像中提取的洪水范围可用于洪水救援管理和改进的城市洪水淹没模型。使用SAR进行城市洪水检测的困难在于，由于其侧视性质，由于雷达停留和建筑物和较高植被造成的阴影，大部分城市地表可能无法被SAR看到。本文研究了是否可以使用（可能被洪水淹没的）地面和相邻建筑物墙壁之间的双重散射来检测中途停留区域（洪水通常可能不明显）的城市洪水。该方法估计双散射强度使用SAR图像结合高分辨率激光雷达（光探测和测距）的城市地区的高度图。将SAR模拟器应用于LiDAR数据，以生成停留和阴影图，并估计SAR图像中双散射曲线的位置。将双散射强度的观测结果与电磁散射模型的预测结果进行比较，对于包含洪水的单个图像，以及变化检测情况，其中将淹没图像与利用相同雷达参数获取的相同区域的未淹没图像进行比较。该方法被证明是成功的，在单图像的情况下，淹没双散射曲线检测到100%的分类精度（虽然使用一个小的样本集）和非淹没曲线91%的分类精度，由于洪水的双散射检测。使用淹没和未淹没图像之间的变化检测实现了相同的成功措施。根据具体的洪水情况，该方法可以改善城市地区的洪水检测。(C)2013作者Elsevier B.V.出版，保留所有权利。
Flooding is a particular hazard in urban areas worldwide due to the increased risks to life and property in these regions. Synthetic Aperture Radar (SAR) sensors are often used to image flooding because of their all-weather day-night capability, and now possess sufficient resolution to image urban flooding. The flood extents extracted from the images may be used for flood relief management and improved urban flood inundation modelling.A difficulty with using SAR for urban flood detection is that, due to its side-looking nature, substantial areas of urban ground surface may not be visible to the SAR due to radar layover and shadow caused by buildings and taller vegetation. This paper investigates whether urban flooding can be detected in layover regions (where flooding may not normally be apparent) using double scattering between the (possibly flooded) ground surface and the walls of adjacent buildings. The method estimates double scattering strengths using a SAR image in conjunction with a high resolution LiDAR (Light Detection and Ranging) height map of the urban area. A SAR simulator is applied to the LiDAR data to generate maps of layover and shadow, and estimate the positions of double scattering curves in the SAR image.Observations of double scattering strengths were compared to the predictions from an electromagnetic scattering model, for both the case of a single image containing flooding, and a change detection case in which the flooded image was compared to an un-flooded image of the same area acquired with the same radar parameters. The method proved successful in detecting double scattering due to flooding in the single-image case, for which flooded double scattering curves were detected with 100% classification accuracy (albeit using a small sample set) and un-flooded curves with 91% classification accuracy. The same measures of success were achieved using change detection between flooded and un-flooded images. Depending on the particular flooding situation, the method could lead to improved detection of flooding in urban areas. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.