AMSR-E/Aqua Monthly Global Microwave Land Surface Emissivity, Version 1

This data set is a global land emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). The data set complements existing land emissivity products from the Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Sounding Unit (AMSU) by adding land emissivity estimates at two lower frequencies, 6.9 and 10.65 GHz (C- and X-band, respectively). Observations at these low frequencies penetrate deeper into the soil layer. Land surface emissivity estimates for this data set were collected at the following vertically and horizontally polarized (V-pol and H-pol) frequencies: 6.9, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz. Ancillary data used in the analysis, such as surface skin temperature and cloud mask, were obtained from International Satellite Cloud Climatology Project (ISCCP). Atmospheric properties were obtained from TIROS Operational Vertical Sounder (TOVS) observations to determine the small upwelling and downwelling atmospheric emissions as well as the atmospheric transmission. The data set is in monthly format that is extracted from instantaneous emissivity estimates. Data are stored in HDF4 files and are available via FTP.

本数据集是基于先进微波扫描辐射计-地球观测系统（Advanced Microwave Scanning Radiometer - Earth Observing System，AMSR-E）的被动微波观测数据构建的全球陆地发射率产品。该数据集补充了现有基于专用传感器微波成像仪（Special Sensor Microwave Imager，SSM/I）与先进微波探测单元（Advanced Microwave Sounding Unit，AMSU）的陆地发射率产品，新增了6.9 GHz与10.65 GHz两个更低频率的陆地发射率估算值，二者分别对应C波段与X波段。此类低频观测可穿透至更深的土层。本数据集的陆地地表发射率估算值覆盖以下垂直极化与水平极化（V-pol、H-pol）频率：6.9、10.65、18.7、23.8、36.5及89.0 GHz。分析中使用的辅助数据（如地表温度与云掩膜）源自国际卫星云气候学计划（ISCCP）。大气特性数据取自泰罗斯业务垂直探测仪（TIROS Operational Vertical Sounder，TOVS）的观测结果，用于计算微弱的大气上行与下行辐射以及大气透射率。本数据集采用月度格式，从瞬时发射率估算值中提取生成，数据以HDF4文件存储，可通过文件传输协议（FTP）获取。