AMSR-E全球陆表被动微波遥感发射率数据集（2002-2011）

地表微波发射率表征了地物向外发射微波辐射的能力，星载被动微波发射率可在宏观、大尺度上对陆表微波辐射进行整体表达，是被动微波地表参数定量反演中经验参数获取的重要基础数据，也是在大尺度上理解陆表微波辐射的一种途径。本数据集考虑到搭载在Aqua卫星上的高级微波扫描辐射计（AMSR-E）和中分辨率成像光谱仪（MODIS）的同步观测特点，采用MODIS的地表温度和大气水汽数据作为输入，通过考虑大气影响的发射率估算模型，生产了全球晴空条件下AMSR-E传感器运行期间（2002年6月~2011年10月）的陆表多通道双极化微波瞬时发射率。通过产品低频无线电信号影响、数据间比对、统计分析、不同地表覆盖条件的发射率特征、频率依赖和相关性研究等开展验证性分析，结果表明瞬时发射率的动态细节丰富，月内日变化标准差在0.02以内，其时空变化、频率依赖和相关性符合自然物理过程的理解。

此套数据集包括AMSR-E全生命周期的全球陆表逐日、侯、旬、半月及月产品，可用于开展星载被动微波遥感模拟、陆面模型以及陆表温度、积雪、大气降水/水汽/可降水量等反演研究。数据的投影坐标采用标准的EASE-GRID投影，数据存储方式为二进制浮点型格点（矩阵大小为1383*586），数据获得之后可用ENVI/IDL等软件或者相应程序代码以二进制文件的方式读取。

所生产出的所有陆表发射率数据按照以下规则命名：
RADI_AMSRE_EM##_yyymmdd_EG_V##.bin
例如文件名称：RADI_AMSRE_EM01_20060101_EG_V#其中
EM##: 01表示每日，05表示5天，10表示旬，HM表示半月，MO表示月
yyyymmdd: yyyy表示年份，mm表示月份，dd表示日期
V##: 版本号，如0.1, 1.0等，个位数为正式版
RADI: “中国科学院遥感与数字地球研究所”英文缩写
AMSRE: 高级微波扫描辐射计

Surface microwave emissivity characterizes the ability of surface features to emit microwave radiation outward. Space-borne passive microwave emissivity can comprehensively represent land surface microwave radiation at a macroscopic, large scale, serving as an important fundamental dataset for acquiring empirical parameters in the quantitative inversion of passive microwave land surface parameters, as well as a means to understand land surface microwave radiation at large scales.

This dataset leverages the synchronous observation characteristics of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite. It uses MODIS land surface temperature and atmospheric water vapor data as inputs, and employs an emissivity estimation model that accounts for atmospheric impacts, to produce global land surface multi-channel dual-polarization microwave instantaneous emissivity under clear-sky conditions during the operational period of the AMSR-E sensor (June 2002 to October 2011).

Validation analyses were conducted, including correction for low-frequency radio interference in the products, inter-data comparison, statistical analysis, emissivity characteristic studies under different land cover conditions, frequency dependence and correlation analyses. The results show that the instantaneous emissivity has rich dynamic details, with the standard deviation of daily variations within a month being less than 0.02. Its spatiotemporal variations, frequency dependence and correlation conform to the understanding of natural physical processes.

This dataset includes global daily, pentad, dekadal, half-monthly and monthly land surface products covering the entire lifecycle of AMSR-E. It can be used for space-borne passive microwave remote sensing simulation, land surface model development, and inversion studies of land surface temperature, snow cover, atmospheric precipitation/water vapor/precipitable water and other parameters. The data adopts the standard EASE-GRID projection coordinate system, and is stored as binary floating-point grid data with a matrix size of 1383 × 586. The data can be read as binary files using software such as ENVI/IDL or corresponding program codes after acquisition.

All produced land surface emissivity data follow the following naming convention:
"RADI_AMSRE_EM##_yyymmdd_EG_V##.bin"
For example: "RADI_AMSRE_EM01_20060101_EG_V#"
Where:
- EM##: 01 denotes daily, 05 denotes 5-day (pentad), 10 denotes dekadal (10-day), HM denotes half-monthly, MO denotes monthly
- yyyymmdd: yyyy represents year, mm represents month, dd represents day
- V##: version number, e.g., 0.1, 1.0, etc., single-digit versions are official releases
- RADI: abbreviation of the Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences
- AMSRE: Advanced Microwave Scanning Radiometer-Earth Observing System

搜集汇总

背景与挑战

背景概述

该数据集提供了2002年至2011年全球陆表被动微波遥感发射率数据，时间分辨率为日，数据大小为19.83 GB，采用EASE-GRID投影存储。数据集通过MODIS地表温度和大气水汽数据输入，结合大气影响模型生产，适用于星载被动微波遥感模拟和陆表参数反演研究。