介绍另一种在轨卫星传感器绝对辐射定标——辐照度基法定标，并利用敦煌辐射校正场对FY-1C卫星可见近红外通道进行定标。通常的反射率基法定标，表观反射率计算的一个重要误差来源是对气溶胶散射的近似计算。辐照度基法定标采用实际测量的漫射与总辐射比来代替辐射传输计算的气溶胶散射。利用该方法对FY-1C卫星的5次定标结果表明，大部分日期辐照度基法和反射率基法定标结果非常吻合，肯定了辐照度基法的正确性，但在气溶胶含量较大时，辐照度基法提高定标精度的优点显现出来，能够减少辐射传输模式对气溶胶散射计算带来的误差，提高最终的绝对辐射定标精度。

This paper describes another in flight method for satellite sensor absolute radiometric calibration, named irradiance based method which was used to calibrate the VIR channels of FY 1C with Dunhuang site. The inaccuracies of apparent reflectance computed by usual reflectance based method can be dependent on the aerosol scattering by assuming aerosol model. Irradiance based method substitute the measured ratio of diffusion to global irradiance to the aerosol scatter computed by radiance transfer code. Calibration results in five times show that the very good agreement with the reflectance based method for most dates confirm the validity of the irradiance based method. But the higher accuracy of the irradiance based method appears in the day when there is high aerosol.