摘要
目前,我国大部分遥感传感器的大气层外波段平均太阳光谱辐照度(Mean solar exoatmospheric irradiances over band b,简称ESUNb)尚未公布,这给遥感图像表观反射率的计算带来了不便,在一定程度上影响了数据资料的应用和推广。本文基于已有官方ESUNb值的EO1/ALI、Terra/ASTER、QuickBird等多种中、高空间分辨率传感器,对9条常见的太阳光谱曲线进行比较分析。结果表明,WRC太阳光谱曲线最合适计算中分辨率传感器的ESUNb,而Wehrli太阳光谱曲线最合适计算高分辨率传感器的ESUNb。基于WRC太阳光谱曲线和Wehrli太阳光谱曲线计算,得到了ZY-1 02C/PMS相机、ZY-3/TLC相机和MUX相机,以及GF-1/WFV相机和PMS相机各波段ESUNb值,并对ESUNb值的不确定性进行了分析。结果显示,太阳光谱选取的不同,对ESUNb的取值会产生-1.94%至1.48%的偏差。本文使用多种卫星传感器交叉比较的方式确定了最佳的太阳光谱,给出了ZY-1 02C、ZY-3和GF-1等卫星搭载的遥感传感器各波段的ESUNb值,为这些国产卫星遥感数据的广泛应用提供便利。此外,本文所用方法简便易行,在其他新的遥感传感器上具有推广应用价值。
Mean solar exoatmospheric irradiances over band b（ESUNb） is an important parameter for computing apparent reflectance. In recent years, ZY-1 02C, ZY-3 and GF-1 were launched and they have played an important role in land and resources survey as well as urban planning and construction. However, ESUNbvalues of these domestic remote sensing satellites have not been released publicly, and till now it causes difficulties in processing their DN values to the physical quantities. In order to calculate ESUNbvalues, Extraterrestrial Solar Spectral Irradiance and Spectral Response Function（SRF） are necessary. This paper aimed to calculate the unknown ESUNbbased on a selection of optimal solar spectrum from nine released solar spectra, including ASTM-E490,WRC, Wehrli, etc. A number of medium spatial resolution and high spatial resolution sensors whose ESUNbhad been officially released were chosen, such as EO1/ALI, Terra/ASTER, QuickBird, etc. Through calculating the mean absolute error（MAE） and the standard deviation of absolute error（SDAE） between the calculated ESUNb values and the officially released values for these sensors, WRC solar spectrum and Wehrli solar spectrum were selected as the optimal solar spectra for sensors with medium spatial resolution and high spatial resolution respectively. This is because WRC solar spectrum showed the least MAE（3.208 W· m^2· μm^-1） and Wehrli solar spectrum showed the least MAE（0.701 W· m^2· μm^-1） and SDAE（1.034 W· m^2· μm^-1）. Based on WRC solar spectrum and Wehrli solar spectrum, ESUNbvalues of ZY-1 02C/PMS, ZY-3/Multispectral camera and Three-line array camera, GF-1/WFV and PMS were calculated and given accordingly. The resultant values were between the maximum and minimum ESUNbvalues for all the nine solar spectra. In addition, the uncertainty analysis was conducted and their relative biases due to the selection of different solar spectra were between-1.938% and 1.477%.Calculating ESUNbvalues in this way is simple and easy, because it can ensure the comparability of data between different remote sensors. This method can be applied to the other new remote sensing sensors so as to fully utilize their data.
出处
《地球信息科学学报》
CSCD
北大核心
2014年第4期621-627,共7页
Journal of Geo-information Science
基金
国家自然科学基金项目(41201358)
上海市科委重点支撑项目(13231203804)
