基于风云三号卫星的全球沙尘遥感方法

新一代风云三号卫星的成功发射,使面向全球沙尘发生、发展和传输的监测分析成为可能。本文利用风云三号卫星可见光红外扫描辐射计(VIRR)数据,深入阐述了沙尘遥感的物理原理,完成了多通道沙尘光谱特性分析,提出了综合沙尘遥感识别方法。结果表明:(1)近红外1.6 μm通道对沙尘存在明显的直方图峰值区,适合沙尘的动态识别;(2)中红外3.7 μm通道的反射和辐射融合特性,可以明显地区分沙尘与其他景观物;(3)红外分裂窗通道对干燥沙尘有不同的吸收衰减,这个差异对于弱沙尘的识别有重要意义。同时,本文给出了基于1.6 μm通道e指数和红外分裂窗通道比值指数的沙尘强度指数计算方法,可以定量地获得全球沙尘的强度分布。本文给出的全球4大沙尘暴多发区同一天出现沙尘天气的实例,体现了风云三号卫星极强的全球观测能力。

Global Dust Remote Sensing with the FengYun-3 Satellite

The FengYun-3 (FY-3) series is the second generation of Chinese sun-synchronous meteorological satellites. The global observation data of FY-3 series can be implemented to monitoring and analysis of the emission, development, and transportation of the dust weather worldwide. In this paper, the Visible and InfraRed Radiometer (VIRR) data of FY-3 series satellite were used to explain the physical principles of the dust weather remote sensing, to analyze the multi-channel spectral characteristics of the dust, and to present the integrated remote sensing detection algorithm of the dust weather. The obvious histogram peak value at near-infrared channel (1.6 μm) can be applied to the dynamic identification of the dust weather. The reflection and radiation fusion characteristics of infrared channel (3.7 μm), can clearly distinguish dust from other objects. There exists difference of the absorption attenuation in the two infrared split window channels of the dry dust, this fact is meaningful for detect the weak dust. Built on the e-index of near-infrared channel (1.6 μm) and the infrared split window channel ratio index, the algorithm of dust intensity index was presented in this paper, which can indicate the global dust intensity distribution quantitatively. The instance of dust weather occurrence on the same day in four sandstorm-prone areas in the world reflects that the global observing capability of FY-3 series.