【作者】 郎姝燕；

【导师】 董晓龙；

【作者基本信息】 中国科学院研究生院（空间科学与应用研究中心） ， 电磁场与微波技术， 2008， 硕士

【摘要】 星载微波散射计是同时测量海面风速和风向的非常有效的遥感手段,可提供全球、全天候、高精度、高分辨率和短周期的海面风场数据。本文主要论述了笔形波束圆锥扫描散射计的系统仿真和影响后向散射系数测量精度的因素,探索了改善散射计系统性能的途径。本文详细论述了微波散射计仿真系统的结构,定义了各模块功能。根据散射计的测量原理,选择后向散射系数的标准差K p为散射计测量精度的度量,并总结了K p的算法。本文对微波散射计测量精度模型主要从两个角度进行了仿真与分析。一方面是改变散射计系统的信号带宽,得出在分辨单元不变的情况下,笔形波束圆锥扫描散射计对于不同输入风场的表现。并分析了有效采样点与信噪比在低速、中等风速、高速风场中对后向散射系数测量精度的影响。此外,还引入了风场反演的评价参数——品质因子(FoM)来进一步分析后向散射系数测量精度对风场反演的影响。之后,根据仿真结果,选出表现最优的散射计系统与SeaWinds散射计进行比较,分析两种系统的优劣。另一方面是改变空间分辨率,得到散射计系统测量精度与反演精度随不同分辨率的变化。上述结论可以为新一代微波散射计的系统设计与实现提供参考和依据。更多还原

【Abstract】 Spaceborne microwave scatterometer can effectively measure wind speed and direction of sea surface. It can provide global, all-day, high-accuracy, high-resolution and short cycle of sea surface wind data. This article focuses on the system simulation of pencil beam conically scanning scatterometer and factors which impact on the backscattering coefficient measurement accuracy, and explores the way to improve system performance.This article discusses in detail the structure of the scatterometer simulation system, and then defines the function of each module. According to the scatterometer measuring principle, we choose the backscattering coefficient standard deviation K p as the study object, and summed up the algorithms.In this paper, we simulate and analyze microwave scatterometer precision model from two perspectives. On the one hand, under the same resolution, when change the scatterometer’s signal bandwidth, we come to the results of different input wind field. Also we analyze how the signal to noise ratio (SNR) of the returned signal from sea surface and the number of independent samples of backscattering measurement impact K p.In addition, we also introduce the wind retrieval evaluation parameter- FoM which can further analyze the impacts of K p on the wind vector retrieval accuracy. According to the simulation results, the scatterometer systems with best performances have been selected to compare with SeaWinds scatterometer.On the other hand, when change the spatial resolution, we get the conclusion that the accuracy of backscattering coefficient measurement and the wind vector retrieval accuracy will change with the resolution. These conclusions above could offer references for the design and realization of next generation of spaceborne microwave scatterometer.更多还原