敦煌场地CBERS-02 CCD传感器在轨绝对辐射定标研究

对资源一号卫星02星（CBERS-02）,为深入其定量化分析,定期在敦煌绝对辐射校正场地进行了地面同步测量,开展了更新在轨绝对辐射定标研究。另外,运用地表反射率和大气光学特性参量数据,计算出CBERS-02CCD传感器4个波段的绝对辐射标定系数。同时,利用2004年8月25目的Landsat-5 TM图像数据对CBERS-02 CCD传感器的辐射特性进行交叉定标,验证分析了CBERS-02 CCD传感器场地绝对辐射定标的基本特性及其可靠性。另外,为CBERS后续星的传感器改进,提供了分析参量。

In-flight Absolute Calibration of the CBERS-02 CCD Sensor at the Dunhuang Test Site

Since(CBERS- 02) was successfully launched on October 21,2003,the data of(CBERS- 02) has been widely applied to the fields for agriculture,forestry,geology,water conservancy ect.It is very necessary to update the coefficient of absolute radiometric calibration in order to deeply carry on the research of quantitative approaches.Therefore,China Centre for Resources Satellite Data & Application team has conducted a field measurement campaign for the characteristic of ground reflectance and of the atmosphere.The results show that the test site of Dunhuang is very homogeneous and the variation of ground material reflectance is about 5%.The results of atmospheric measurements have shown that the aerosol optical depth(<0.14) is very low.The coefficients of CBERS- 02 CCD sensor for four bands have been obtained through the "6S" atmospherical transfer code.Simultaneously,the cross-calibration of Landsat-5 TM and CBERS- 02 CCD based on the image of August 25,2004 was made.It shows that the consistency between the results from Dunhuang site calibration and cross-calibration varies less than 6% except band 3.The field measurement verified the radiometric performance and reliability for the absolute calibration of CBERS- 02 CCD sensor.