雷达卫星TerraSAR-X精准测距高原湿地水位反演研究

发布时间：2018-06-17 15:02

本文选题：湿地水位 + TerraSAR-X　；参考：《北京交通大学》2017年硕士论文

【摘要】：湿地的特殊性和重要性已受到世界各地的广泛关注,水位更是湿地生态健康状况的关键参数。遥感技术由于其空间分辨率高、覆盖范围广以及人工经济成本低的优势已广泛应用于湿地调查中,但应用于水位监测方面的研究较少。实现遥感技术测量水位可以减少长期多次的野外工作,实现高效、持续的监测。本论文基于国家自然基金委员会面上项目多时相多极化SAR高原湿地关键水文和植被参数遥感反演研究,针对光学数据、激光高度计以及雷达高度计在湿地水位反演方面的不足,充分挖掘TerraSAR-X精确测距的能力,集中解决影响高原湿地水位反演的问题。主要研究工作和结论如下:(1)研究了 SAR观测过程大气折射方法,对大气相位进行了定量分析,建立对流层干延迟和湿延迟与水汽参数之间的模型,实现了雷达图像大气延迟的计算程序,得到了在可鲁克湖地区10月份时大气对雷达信号可造成1.5米以上延迟的结论。(2)研究了 SAR观测过程地球物理效应的改正方法,通过分别建立固体潮、大气荷载和极潮对观测站位移影响的模型,实现了地球物理效应对观测点影响的计算,对地球物理效应与SAR斜距的数学关系进行了探讨,得到了地球物理效应会对SAR斜距产生分米级影响的结论。(3)基于大气延迟模型、地球物理效应修正方法及角反射器的精确定位,实现了雷达卫星TerraSAR-X的精准测距。用SAR卫星瞬时位置与角反射器位置解算距离信息进行检验,两者相差5.4cm,验证了 TerraSAR-X精准测距的可行性。(4)研究角反射器在SAR影像上的响应特征,建立修正后的TerraSAR-X精准测距、角反射器成像时SAR卫星瞬时位置和角反射器位置之间的数学关系,实现两幅影像间水位变化的计算。通过在实验区安置水位计进行检验,两者相差4.8cm,验证了 TerraSAR-X精准测距反演湿地水位的可行性及精度。
[Abstract]:The particularity and importance of wetland have been paid more and more attention all over the world, and water level is the key parameter of wetland ecological health. Remote sensing technology has been widely used in wetland survey due to its advantages of high spatial resolution, wide coverage and low cost of artificial economy, but less research has been done on water level monitoring. The remote sensing technique can reduce the field work for a long time and realize high efficiency and continuous monitoring. This paper is based on the research of remote sensing inversion of key hydrological and vegetation parameters of multi-phase multi-polarization SAR wetland on the surface of the National Natural Fund Committee, aiming at the shortcomings of optical data, laser altimeter and radar altimeter in the inversion of wetland water level. The ability of TerraSAR-X precise ranging is fully exploited and the problems affecting the inversion of water level in plateau wetland are solved. The main research work and conclusions are as follows: (1) the atmospheric refraction method during SAR observation is studied, the atmospheric phase is quantitatively analyzed, and the model between dry and wet troposphere delay and water vapor parameters is established. The calculation program of atmospheric delay in radar image is realized, and the conclusion that atmospheric delay to radar signal can be more than 1.5 meters in October in Lake Kerouk region is obtained. The correction method of geophysical effect in SAR observation process is studied. By establishing the models of the effects of solid tide, atmospheric load and polar tide on the displacement of observation station, the effect of geophysical effect on observation point is calculated, and the mathematical relationship between geophysical effect and SAR slanting distance is discussed. The conclusion that geophysical effect will have a decimeter effect on SAR slant distance is obtained. Based on atmospheric delay model, geophysical effect correction method and precise location of angle reflector, the precise ranging of radar satellite TerraSAR-X is realized. The difference between instantaneous position of SAR satellite and angular reflector is 5.4 cm, which verifies the feasibility of TerraSAR-X precise ranging. (4) the response characteristics of angle reflector in SAR image are studied, and the modified TerraSAR-X precise ranging is established. The mathematical relationship between the instantaneous position of the SAR satellite and the position of the angular reflector during the imaging of the angular reflector is used to calculate the variation of the water level between the two images. The difference between the two is 4.8 cm, which verifies the feasibility and accuracy of TerraSAR-X precise distance measurement for retrieving the water level of wetland.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P237

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