介绍了一种采用深对流云目标对风云二号（FY-2）扫描辐射计可见光通道进行辐射定标的方法。 以深对流云作为辐射定标参考载体, 以AQUA/MODIS获得的深对流云反射率作为辐射基准参考, 以GOME-2和辐射模式模拟的DCC光谱进行了光谱响应函数的修正, 评估FY-2系列卫星的可见光通道辐射定标精度及其长序列衰减趋势。 结果表明: （1）FY-2可见光通道存在不同程度的衰减, FY-2D, FY-2E和FY-2F的年衰减率分别约为1.67%, 1.69%和0.81%; （2）与国际推荐的参考仪器AQUA/MODIS的DCC反射率基准相比, 风云二号可见光通道业务定标结果与之存在显著差异, 其相对偏差了分别达到了39.9%, 29%和19.2%。 （3）FY-2卫星在轨期间, 可见光通道存在一定程度的周期性的波动和跳跃现象。 借助深对流云目标很好地实现了FY-2系列气象卫星的可见光辐射定标, 获取的辐射定标结果已经作为业务定标更新的重要依据。

A radiometric calibration method is described in this paper by using the deep convective clouds (Deep Convective Cloud, DCC) target for FY-2 visible channel. The deep convective cloud can be used as the radiometric calibration transfer object. The on-operational FY-2 radiometric calibration bias and the long-term degradation trend are evaluated according to the AQUA/MODIS instrument as the baseline of radiometric reference and DCC. The results show that: (1) There are different degrees of degradation for FY-2D, FY-2E and FY-2F, among which FY-2D has the biggest degradation due to the longest period. The annual rates of degradation for FY-2D and FY-2E are quite similar, 1.67% and 1.69% respectively, whereas the rate for FY-2F is lower with 0.81%; (2) During the period of satellite eclipse, the instruments are not stable and this phenomenon could be detected by the DCC method; (3) There are bias in the the operational radiometric calibration between FY-2 and AQUA/MODIS, which is treated as the the radiometric reference usually. The radiometric calibration method based on DCC could work well in the radiometric calibration for FY-2. The results will help us to understand the degradation of instrument and for quantitative application usage.