青藏高原FY-4A地面太阳辐射精细化评估数据集（2019-2021）

数据为青藏高原地区FY-4A地面太阳辐射产品，包括GHI\DNI\DIF.FY4地表太阳入射辐射反演算法涉及的通道包括成像仪可见光、近红外和短波红外的6个通道：CH1(0.45-0.49微米)、CH2(0.55-0.75微米)、CH3(0.75-0.90微米)、CH4(1.36-1.39微米)、CH5(1.58-1.64微米)、CH6(2.1-2.35微米)。算法依赖的回归模型需要事先通过辐射传输模拟和统计分析建立，回归模型定义了地表太阳入射辐射与成像仪多通道辐射观测之间的回归关系式，是太阳观测几何与最重要影响参数（云、气溶胶、水汽含量、地表反照率、地表海拔高度等）的函数。算法利用FY-4卫星成像仪通道1至通道6的短波辐射观测，来获取大气和地表的瞬时状态参数信息，同时由地表高程数据获取地表海拔高度信息。在确定瞬时的大气和地表状态后，结合太阳角度和观测角度，根据事先建立的回归模型数据，进行多维线性插值，获取地表太阳入射辐射反演产品。

The dataset consists of FY-4A ground surface solar radiation products over the Qinghai-Tibet Plateau, including GHI, DNI, and DIF. The retrieval algorithm for FY-4 surface incident solar radiation involves 6 channels of the imager covering visible, near-infrared and shortwave infrared bands: CH1 (0.45–0.49 μm), CH2 (0.55–0.75 μm), CH3 (0.75–0.90 μm), CH4 (1.36–1.39 μm), CH5 (1.58–1.64 μm), and CH6 (2.1–2.35 μm). The regression model relied on by the algorithm needs to be established in advance via radiative transfer simulations and statistical analysis. This model defines the regression relationship between surface incident solar radiation and multi-channel radiometric observations from the imager, and it is a function of solar observation geometry and key influencing parameters including clouds, aerosols, water vapor content, surface albedo, and surface elevation. The algorithm utilizes shortwave radiation observations from Channels 1 to 6 of the FY-4 satellite imager to acquire instantaneous state parameter information of the atmosphere and surface, while obtaining surface elevation data from topographic elevation datasets. After confirming the instantaneous atmospheric and surface states, combined with solar and observation angles, multi-dimensional linear interpolation is performed based on the pre-established regression model data to obtain the surface incident solar radiation retrieval products.