HJ-1A星辐射定标及近海水体大气校正的精度验证

Precision Verifications of Radiance Calibration and Coastal Water Atmospheric Correction for Satellite HJ-1A

以应用HJ-1A星数据进行近海水体定量反演为目的,对HJ-1A星CCD的星上定标系数的精度进行验证,并基于Landsat-5TM数据对其进行交叉定标。在此基础上反演近海水体的反射率,将反演结果与实测水体反射率进行比较发现:对HJ-1A星CCD数据进行交叉定标能在一定程度上能提高近海水体反射率反演的精度。结果表明,HJ-1A星CCD影像的星上定标系数不够精确,在利用该数据进行近海水体的定量反演研究时,需要利用交叉定标对星上定标参数进行修正。

For the purpose of quantitative inversion in coastal waters by using the CCD data of Satellite HJ-1A,the precision of radiance calibration coefficients of the CCD mounted on Satellite HJ-1A was validated and a cross radiance calibration was performed based on the data from Landsat-5 TM.And then,an inversion was made of the reflectivity of coastal waters on the basis of all these data.By comparing the results from the inversion and those from the measurements,it has been found that the cross radiance calibration for the CCT data of Satellite HJ-1A can,to a certain extent,improve the precision of the inversion of the reflectivity of coastal waters.These results indicate that the onboard radiance calibration coefficients of the CCD images on Satellite HJ-1A are not precise so enough that the cross radiance calibration should be also applied when the CCD data from Satellite HJ-1A are used to carry out the quantitative inversion in the coastal waters.