针对高分辨率卫星遥感反演气溶胶光学厚度地表噪声难以分离的问题,利用国产"高分一号"(GF-1)的数据特点,提出了一种气溶胶光学厚度反演方法和处理流程。该方法分别基于暗像元和深蓝算法去除了浓密植被和城市亮目标地区的地表贡献,并应用于我国污染较为严重的京津冀、长三角、珠三角等示范区域。利用北京、杭州、香港AERONET地基观测数据,对GF-1反演得到的气溶胶光学厚度进行验证,结果表明:气溶胶高值均集中在三大区域工业排放大和人类活动密集的核心城市,年均光学厚度值在1左右。卫星和地基的相关性总体较好,三大区域的相关系数分别达到了0.71、0.55、0.54。受云识别、亮地表覆盖和气溶胶模式假设等影响,GF-1反演的气溶胶光学厚度存在一定程度的偏差。
The surface noise is difficult to separate when using the high resolution remote sensing data to retrieve the Aerosol Optical Depth(AOD).Based on the characteristics of GF-1data,the method and data processing procedure of AOD retrieval are developed in this study.The surface contribution over dense vegetation and urban bright target areas are respectively removed by using the dark target and deep blue algorithms.This method is applied for the three serious polluted Beijing-Tianjin-Hebei(BTH),Yangtze River Delta(YRD)and Pearl River Delta(PRD)regions.The retrieved AOD are validated by ground-based AERONET data from Beijing,Hangzhou,and Hongkong sites.The results show that:1)The heavy aerosol loadings are usually distributed in high industrial emission and dense populated cities,with the AOD value near 1.2)There is a good agreement between satellite-retrievals and in-site observations,with the coefficient factors of 0.71(BTH),0.55(YRD)and 0.54(PRD).3)The GF-1retrieval uncertainties are mainly from the impact of cloud contamination,high surface reflectance and assumed aerosol model.