中国资源卫星应用中心于2005年8月，利用敦煌场地分别对CBERS-02CCD和SPOT-4 HRVIR1两个传感器进行在轨绝对辐射定标。本文对此次地面同步测量数据进行了处理分析，基于反射率法计算出了CBERS-02CCD和SPOT-4HRVIR1两个传感器各波段的定标系数。其中，SPOT-4HRVIR1的定标结果与法国官方8月份提供的定标系数相比，差异在6％内，满足法方对绝对辐射定标精度的要求。此外，应用定标系数分别将两个传感器的图像数据反演成地表反射率图像，对它们进行了对比分析。

The In-flight absolute calibrations were performed for CBERS-02 CCD and SPOT- 4 HRVIR1 sensors by China Center for Resources Satellite Data and Applications(CRESDA) on August,2005 at Dunhuang test site.The absolute calibration coefficients were obtained for different bands of the two sensors using the method based on reflectance and the data processing and analyses for the simultaneous ground-based measurements.Meanwhile,the relative differences of calibration coefficients were small within and 6% compared with the results provided by France officialy in pulolished data August for SPOT- 4 HRVIR1 sensor.It satisfied the calibration error requirements by France side.The comparison and analysis were completed by using the coefficients of two sensors respectively to convert their original images to target reflectance images.