Landsat 8卫星OLI传感器波段平均太阳辐照度计算

卫星传感器波段平均太阳辐照度(solar exoatmospheric spectral irradiances,简称ESUN)是反演地表温度、大气顶部反射率的重要参数。目前,Landsat 8卫星的传感器ESUN值美国地质调查局仍未公布。采用ChKur、WRC、Thuillier、ASTM和Wehrli太阳光谱数据,结合Landsat 8卫星的相对光谱响应数据,使用代入计算的方法分别计算了OLI传感器各波段的ESUN值。与ChKur数据计算的结果相比,应用Wehrli数据计算的结果均方根误差最小,使用WRC数据计算的结果均方根误差最大。为验证结果,用同样的方法计算了基于ChKur太阳光谱数据的Landsat 7卫星ETM+传感器的ESUN值,并与美国地质调查局官方推荐的结果做对比,结果表明,基于ChKur太阳光谱数据采用该方法计算结果较为符合官方数据。

Calculation of solar exoatmospheric spectral irradiances of Landsat 8 satellite OLI sensor

Satellite sensor solar exoatmospheric spectral irradiances(ESUN)are the key parameters to retrieve land surface temperature or calculate top of atmosphere reflectance.The United States Geological Survey(USGS)has not announced the recommended ESUN values of Landsat 8 satellite at present.The authors selected ChKur,WRC,Thuillier,ASTM and Wehrli solar spectrum datasets,combined with Landsat 8 satellite relative spectral response data,and calculated ESUN of Landsat 8 OLI sensor by method of substitution.Compared with ChKur data,the results calculated based on Wehrli data have the smallest root mean square error(RMSE),while the results calculated based on WRC data have the largest RMSE.In order to verify the results,the authors calculated ESUN values of Landsat 7 ETM+sensor based on ChKur solar spectrum dataset,then compared with USGS results.It shows that based on the ChKur solar spectral curve,the results calculated by this method match the official data better.