白天和夜间通用的卫星遥感沙尘判识算法构建与验证分析

Himawari-8是日本发射的新一代静止气象卫星,与前一代的MTSAT-2相比,在时间、空间分辨率上都有了很大提升,特别是红外通道数量从4个增至10个,为红外遥感沙尘提供了新的观测数据。本研究利用Himawari-8的红外观测数据,发展了仅用红外通道的沙尘全天候判识算法,可以实现对白天和夜间的连续监测。算法在前人基础上去除了可见光通道,同时引入更多红外通道来进行云检测和沙尘判识。由于一日之中,地表温度发生变化,因此针对白天和夜间设置了两套不同的判别阈值,来保证算法的全天适用性。最后通过两次沙尘事件对沙尘判别结果的分析和检验表明,遥感判识结果与地面气象站和PM_(10)观测较为一致,说明了只用红外通道全天候判识沙尘的可行性。

Construction and Validation of Remote Sensing Dust Recognition Algorithm in Daytime and Nighttime

Himawari-8 is a new generation of geostationary meteorological satellite launched by Japan. Compared with the previous generation of MTSAT-2, it has greatly improved its spatio-temporal resolution. The number of infrared channels of Himawari-8 is increased from 4 to 10 compared with MTSAT-2, providing new observation data for infrared remote sensing of dust. This research makes full use of Himawari-8 infrared observation data and develops an all-day dust identification algorithm using only infrared channels, which can realize continuous monitoring during the day and night. The algorithm is based on previous algorithms, and does not use visible light channels, but uses more infrared channels for cloud detection and dust recognition. As surface temperature changes during the day, two different sets of discriminant thresholds are set up for daytime and nighttime to ensure the applicability of the algorithm for the whole day. Finally, two dust events are used to verify the results of dust discrimination. The consistency between ground-based and remote sensing results shows that it is feasible to use the infrared channel to identify sand and dust all day.