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    基于Landsat8数据的2种海表温度反演单窗算法对比——以红沿河核电基地海域为例

    A comparison of two mono-window algorithms for retrieving sea surface temperature from Landsat8 data in coastal water of Hongyan River nuclear power station

    • 摘要: 以辽宁省红沿河核电站附近海域为研究区,对单窗算法用于Landsat8 TIRS数据反演沿海海表温度(sea sur-face temperature,SST)的适用性进行比较分析.首先,基于大气廓线数据(thermodynamic initial guess retrieval, TIGR),针对 Landsat8 TIRS第10波段修订QK&B算法系数;然后,从星地同步验证和参数敏感性2方面对辐射传输模型(radiation transfer model,RTM)和QK&B算法进行对比分析.结果表明,结合美国国家环境预报中心(Na-tional Centers for Environmental Prediction,NCEP) 大气参数实现的RTM算法精度较QK&B算法略高;对于QK&B算法,基于NCEP廓线数据模拟的大气透过率比经验方程估算的值更具优势;RTM算法对大气透过率敏感性相对较高,且明显高于QK&B算法;而 QK&B算法对大气平均作用温度的敏感性较高;RTM算法对大气透过率、大气上行辐射以及QK&B算法对大气透过率、大气平均作用温度的敏感性均随着水汽含量的增加而增大.

       

      Abstract: Two mono -window algorithms, i. e., radiation transfer model (RTM) and QK&B algorithm, were evaluated and compared for their performance on sea surface temperature (SST) calculation from Landsat8/TIRS data in coastal water of Hongyan River nuclear power station. The parameters of QK&B algorithm were modified for Landsat8 thermal infrared band 10 based on thermodynamic initial guess retrieval(TIGR) atmospheric profile data, and both atmospheric transmittance values obtained from water vapor content based on empirical model and from National Centers for Environmental Prediction (NCEP) data were employed for QK&B algorithm respectively with the purpose of comparing their feasibilities for SST retrieval. A validation with shipboard measurements of SST collected synchronically shows that the slightly better accuracy in SST retrieval is observed from RTM method(RMSE = 0. 525 0) than from modified QK&B algorithm (RMSE = 0. 638 0). QK&B algorithm using atmospheric transmittance simulated using NCEP data provided better accuracy than that using atmospheric transmittance estimated from water vapor content. Sensitivity analysis based on data simulated by MODTRAN4.0 using NCEP data was conducted. The results show that atmospheric transmittance has the greatest impact on the accuracy of SST retrieval among all parameters input RTM method, followed by atmospheric upward radiation. Atmospheric transmittance also shows greater sensitivity for RTM method than that for QK&B algorithm. For QK&B algorithm, atmospheric average temperature has greater impact on SST retrieval than other parameters input. Atmospheric upward radiation for RTM method, atmospheric average temperature for QK&B algorithm and atmospheric transmittance for both two algorithms show increasing impact on SST retrieval with increasing water vapor content.

       

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