摘要
HJ-1B卫星自发射以红外通道共进行了7次星上黑体定标,针对星上定标系数的验证工作开展较少,以MODIS第31、32通道为参考源,分别基于光谱响应差异和线性统计关系两种方法对HJ-1B红外通道星上定标系数进行验证。首先,计算两个传感器表观辐亮度的匹配关系,进而计算出HJ-1B红外通道的等效离表亮温,通过与HJ-1B红外通道基于星上定标系数反演得到的离表亮温进行比较,实现对星上定标系数的验证。通过半高宽法、矩方法和查找表法这三种不同的方法计算得到了2009年9月14日星上定标系数。结果表明:三种方法中,查找表法精度较高,且HJ-1B查找表法星上定标系数反演亮温与基于光谱响应差异和线性统计关系计算的等效亮温偏差较小,分别为0.02 K和0.81 K。这两种交叉验证方法的精度均在1 K以内,证明了该方法的可行性,且基于光谱响应差异的验证方法精度更高。该研究为光学载荷在轨辐射定标的验证提供了理论基础。
Since HJ- 1B has been launched, 7 sets of blackbody data were used to calculate onboard calibration coefficients, but the research work on the validation of coefficients is rare. MODIS 31, 32 channels were selected as the reference sensor for the validation of the HJ- 1B infrared channel onboard calibration coefficients by using the methods of spectral response divergence and linear statistical relationship. Firstly, the relationship of top of atmosphere （TOA） radiance between the HJ- 1B thermal infrared channel and MODIS 31, 32 channels is calculated, and based on which the surface leaving brightness temperature is calculated to validate the brightness temperature calculated through the onboard calibration coefficients. According to the onboard calibration principle, calibration coefficients of HJ- 1B infrared channel on Sep 14th ,2009 are calculated with the Half﹣width, moments and look﹣up table methods. The results show that calibration coefficients calculated by the look﹣up table method has better precision. The difference between the brightness temperature of look﹣up table method and spectral response divergence and linear statistical relationship methods are within 1 K, 0.02 K and 0.81 K,respectively, which demonstrate the feasibility of both validation methods and the spectral response divergence method has high accuracy. The study may contribute to fundamental basis for the validation of in﹣flight calibration of optical payload.
出处
《红外与激光工程》
EI
CSCD
北大核心
2014年第11期3638-3645,共8页
Infrared and Laser Engineering
基金
国家高技术研究发展计划(2012AA12A302)
关键词
星上定标
红外
交叉验证
onboard calibration
infrared
cross validation
