基于MODIS数据的云检测及其在新疆的应用

Cloud Detection in Xinjiang Based on MODIS Data

基于遥感手段,以云的可见光和红外波段特性为依据,借鉴国内外多种云检测方法,利用MODIS 1,6,26通道资料,以指数法和光谱阈值相结合的多光谱云检测算法,对新疆山区2009年的MODIS资料进行云检测处理。检测结果的统计分析得出,2009年全疆平均云覆盖日数为82 d,其中山区平均云覆盖日数101 d,平原地区平均云覆盖日数为69 d,云覆盖分布主要集中在山区。

Precipitation is closely related to clouds.Artificial weather stations and weather forecast radar detection are the primary means of cloud observation,but the means are sometimes unable to obtain the comprehensive and accurate cloud cover data due to the natural constraints and human error.Reference to a variety of domestic and foreign cloud detection methods,in this study the multispectral cloud detection algorithm based on the combination of index method and spectral threshold method was used to detect cloud cover conditions over Xinjiang using MODIS1,6,26-channel data.The analyzed results show that the average annual cloud cover duration in Xinjiang in 2009 was 82 days,in which the average annual cloud cover duration was 101 days in the mountainous regions and 69 days in the plains,respectively.