MODIS数据云检测算法在西南地区的改进

The Cloud Detection Improvement and Application of MODIS Data in Southwestern China

根据云在MODIS数据几个可见光和红外波段的特性,改进了现今国内外应用较广泛的多光谱综合云检测算法,进行中国大陆西南地区的云检测应用试验。通过对该区不同时期的云检测应用试验,调整该方法的各光谱阈值。试验结果表明,该多光谱综合云检测法效果理想,对可见光波段难以识别的薄卷云也有很好的效果,为MODIS数据进一步在中国大陆西南地区的应用打下了良好的基础。

According to the characteristics of the cloud on the MODIS data visible and infrared spectra,we improve the domestic and foreign common cloud detection method. We use the Multi-spectrum synthesis cloud detection and in the Southwestern China test. Based on the different periods of cloud detection application test, the spectrum threshold value of the method can be determined. Our test result shows that the effect of Multi-spectrum synthesis cloud detection is ideal especially for the thin cirrus cloud which is invisible in the visible band. The Muhi-spec- trum synthesis cloud detection laid a good foundation for further application of MODIS data in Southwestern China.