摘要
运用合成孔径雷达干涉及其差分技术(InSAR及D InSAR)进行地面微位移监测,是近年来发展起来并得到日益重视的新方法。对不同地区地面形变的最新研究结果表明,合成孔径雷达干涉及其差分技术在地震形变、冰川运移、活动构造、地面沉降及滑坡等研究与监测中有广阔的应用前景,具有不可替代的优势。与其它方法(如GPS监测等)相比,用InSAR及D InSAR进行地面形变监测的主要优点在于:(1)覆盖范围大,方便迅速:(2)成本低,不需要建立监测网;(3)空间分辨率高,可以获得某一地区连续的地表形变信息;(4)可以监测或识别出潜在或未知的地面形变信息:(5)全天候,不受云层及昼夜影响。但是由于系统本身因素以及地面植被、湿度及大气条件变化的影响,精度及适用性受到一定的限制,需要在实践中不断加以完善和提高,并与地质研究及其它方法相结合。为了弥补传统InSAR及D InSAR方法在地面形变监测方面的不足,提高其精度,近期引入了一种称为永久散射点(PS)的方法。此方法通过选取一定时期内表现出稳定干涉行为的孤立点,克服了许多妨碍传统雷达干涉技术的分辨率、空间及时间上基线限制等问题,使InSAR在城市及岩石出露较好地区地面形变监测精度大大提高,在一定的条件下精度可达到mm级。
In recent years, the techniques of Interferometric Synthetic Aperture Radar(InSAR) and differential Interferometric Synthetic Aperture Radar(D-InSAR) have been widely used in surface deformation monitoring, which achieved much attention from many earth scientists. New results on surface deformation surveys from different places show that the techniques of InSAR and D-InSAR have great potential in detecting displacements caused by earthquake deformation, glacier movement, neotectonics, ground subsidence and landslides. Some of the results can't be achieved by other methods.Compared with the conventional approaches(such as GPS monitoring), using of InSAR and D-InSAR in surface deformation monitoring has many advantages. First, the InSAR images can cover a large area on the earth, and the result can be obtained in a relatively short time. Second, there is no need to establish the monitoring network; so the cost is low. Third, the spatial resolution is high and the continue displacement information of the ground can be achieved theoretically. Fourth, the potential or unknown ground displacement can be identified, which is very useful for the rural area or the dangerous places where we can't easily arrive. Finally,because the cloud and the light have no effect on the Synthetic Aperture Radar images, the images can be obtained every times when the SAR satellites pass the area. But the application and accuracy will be influenced because of some inherent factors of InSAR and variations of ground plant, humidity and atmosphere at different time. So the InSAR and D-InSAR approaches should be improved and combined with geological study and other methods.In order to improve the accuracy of InSAR and D-InSAR in monitoring the surface deformation, a new technique, known as the Permanent Scatterers(PS) approach, has been developed recently. By selecting isolated points on the ground which exhibit extremely stable interferometric phase behavior over time, the new approach overcomes most of the resolution, tempeoral and spatial baseline limitations hindering conventional InSAR processing, which has greatly improved the accuracy of InSAR to ground deformation monitoring, especially in the cities or the places where the rocks are well exposed. With the introduction of the PS approach, sometimes the ground displacement can be measured to millimetric accuracy.
出处
《中国地质灾害与防治学报》
CSCD
2004年第1期112-117,128,共7页
The Chinese Journal of Geological Hazard and Control
关键词
合成孔径雷达干涉测量
INSAR
地面形变监测
永久散射点
地质灾害
Interferometric Synthetic Aperture Radar(InSAR)
differential Interferometric Synthetic Aperture Radar(D-InSAR)
surface deformation monitoring
Permanent Scatterers(PS)
geological hazards
