摘要
随着TerraSAR-X、Cosmo-SkyMed和Radarsat-2等高分辨率合成孔径雷达(SAR)卫星系统的升空,星载SAR图像空间分辨率达到了米级。在这些高空间分辨率SAR图像中,单个建筑物结构的散射特征能够得到明显的展现,推动了SAR在城市监测中的应用。而城市环境的复杂性给SAR图像的解译和应用带来了巨大的挑战,由于SAR图像模拟有助于图像的解译和应用,因此城市目标高分辨率SAR图像模拟成为一个研究热点。提出了一种基于射线追踪法的图像模拟方法,它能够模拟城市目标SAR图像上叠掩、阴影和多次散射等主要特征,非常有利于SAR图像的解译。该模拟方法首先构建虚拟SAR传感器,发射电磁波射线与场景中三维模型相互作用,并接收回波信号成像,电磁波的传播以及与场景的多次散射在整个过程中都能够被追踪。为了评价该模拟方法的有效性,首先通过模拟平顶屋、尖顶屋模型的SAR图像,然后选择国家体育馆和大场景小区三维模型作为输入,将生成的模拟图像与真实TerraSAR-X聚束模式图像进行比较。结果表明:该模拟器能够模拟城市目标的散射特征并应用于图像的理解和变化检测。
After Very High Resolution（VHR） radar satellite missions like TerraSAR-X, Cosmo-Skymed and RadarSat-2 have been launched in 2007, spaceborne Synthetic Aperture Radar（SAR） images reach spatial resolution below 1 m in azimuth and range in spotlight mode. In such kind of data, radar signals represen ting single building are disturbuted over a high number of resolution cells, which makes SAR to monitor urban areas possible. However, due to the complexity of urban environment,interpretation and application of SAR data still turns out to be challenging and time consuming. SAR images simulation,which can reduce the difficulty,is becoming increasingly popular. A novel method of SAR images simultion based on extend ed ray tracing procedure was introduced. The simulator, which has an important role in analysis of images, can effectly simulate scatterring effects of SAR images,such as layover,shadow and multiple bounce. First- ly,a virtual SAR system was formed. For the sensor,rays were transmited and received. The pathes of the rays and the interaction with objects were traced by the simulator. Signals from different reflection levels could be stored in seperated image layers. For evaluating the effectiveness of the simulation approach, simu latd images were compared with real TerraSAR-X images for several models like a building with plane-roof and gable-roof,National Gymnasiem and an extended scene containing numbers of building models. The re sults show that the simulation can provide very valuable information to detect interpret complex SAR ima- ges changes.
出处
《遥感技术与应用》
CSCD
北大核心
2013年第4期594-603,共10页
Remote Sensing Technology and Application
基金
中国科学院知识创新工程重要方向项目(KZCX2-EW-320)
国家自然科学基金项目(41001213)
国家863计划项目(2011AA120403)
中国科学院知识创新工程青年人才领域前沿项目(Y0S04400KB)
