为实现海雾的卫星自动监测, 利用大量AVHRR3/NOAA17卫星观测数据, 比较不同目标物(海雾区、不同云系及晴空下垫面)在可见光、近红外波段的反射辐射特性差异, 统计分析了海雾的遥感光学辐射特性。结果表明,海雾区三通道反射率满足RCh1>RCh3a>RCh2, 甚至出现RCh3a>RCh1>RCh2, 不同于其它目标物(RCh1>RCh2>RCh3a)。运用Streamer辐射传输模式模拟了海雾、不同云系在卫星高度处的三通道反射率特性, 从理论上进一步验证了海雾所具有的光学辐射特性, 同时指出, Ch3a的反射率对粒子粒径的响应明显, 即粒子粒径越小, Ch3a的反射率越高。通过米氏散射理论对这一现象进行原因分析。

For sea fog events auto-monitor from satellites, the visible and infrared spectral radiance characteristics of sea fog, water surface, and cloud regions are analyzed based on data analysis from AVHRR3/NOAA17 observations. The remote-sensing optical radiance characteristis of sea fog are analyzed. It is found that there exists obvious spectral difference between sea fog and others. In sea fog region, the satellite-measured reflectance relation of channel 3a (1.58～1.64 μm), channel 1 (0.58～0.68 μm) and channel 2 (0.725～1.0 μm), is RCh1>RCh3a>RCh2 and even RCh3a>RCh1>RCh2, which are different from the RCh1>RCh2>RCh3a of ocean and some cloud bodies. With the Streamer radiative transfer model, the fog and clouds spectral properties of AVHRR3 Channel 1, 2 and 3a are simulated under different fog/cloud microphysical and observational conditions. The simulations are consistent with observations. The reflectance of Channel 3a is affected by the size of particle, that is, the smaller is the size, the higher reflectance is. Finally, those fog and cloud spectral properties are explained with Mie scattering theory.