Aerosol Optical Depth (AOD) is one of the important parameters to characterize the physical properties of the atmospheric aerosol, which is used to describe the extinction characteristics of the aerosol, and also to calculate the aerosol content, to assess the degree of air pollution and to study aerosol climate effect. To study the historical change of aerosol in long-time series, the advanced very high resolution radiometer (AVHRR) data earliest used for aerosol research was used in this study. Due to the lack of shortwave infrared (SWIR) (center at 2.13 µm) of the sensor, the relationship between the blue and red bands with SWIR cannot be provided, and the visible band used to calculate the normalized difference vegetation index (NDVI) contains the wavelength range of red and green, it is very difficult to calculate the accurate land surface reflectance (LSR). Therefore, based on the Dense Dark Vegetation algorithm (DDV), we propose to introduce mature MODIS vegetation index products (MYD13) to correct AVHRR NDVI, to support the estimation of AVHRR LSR, determine the relationship between corrected AVHRR NDVI and visible band LSR, and to carry out aerosol retrieval. The results show that about 63% of the data are within the error line, and there is a consistent distribution trend in the inter-comparison validation with MODIS aerosol products (MYD04).

中文翻译：

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从 NOAA/AVHRR 数据中检索气溶胶光学深度的改进 DDV 算法

气溶胶光学深度（AOD）是表征大气气溶胶物理性质的重要参数之一，用于描述气溶胶的消光特性，也用于计算气溶胶含量，评估空气污染程度和研究气溶胶气候效应。为了研究气溶胶在长时间序列中的历史变化，本研究使用了最早用于气溶胶研究的先进超高分辨率辐射计（AVHRR）数据。由于缺少传感器的短波红外（SWIR）（中心在 2.13 µm），无法提供蓝色和红色波段与 SWIR 的关系，用于计算归一化差异植被指数（NDVI）的可见波段包含红色和绿色的波长范围，计算准确的地表反射率 (LSR) 非常困难。因此，基于Dense Dark Vegetation算法（DDV），我们建议引入成熟的MODIS植被指数产品（MYD13）来修正AVHRR NDVI，支持AVHRR LSR的估计，确定修正后的AVHRR NDVI与可见波段LSR的关系，并进行气溶胶回收。结果表明，约63%的数据在误差线内，与MODIS气溶胶产品（MYD04）的比对验证存在一致的分布趋势。确定修正后的 AVHRR NDVI 与可见波段 LSR 的关系，并进行气溶胶反演。结果表明，约63%的数据在误差线内，与MODIS气溶胶产品（MYD04）的比对验证存在一致的分布趋势。确定修正后的 AVHRR NDVI 与可见波段 LSR 的关系，并进行气溶胶反演。结果表明，约63%的数据在误差线内，与MODIS气溶胶产品（MYD04）的比对验证存在一致的分布趋势。