二类水体的MODIS数据大气校正及在渤海表层水体叶绿素浓度监测反演中的应用研究

Atmospheric correction of modis data for case-ii water and research of monitoring and retrieving chlorophyll concentration in the Bohai Sea

提出一种适用于中国近岸二类水体的大气校正方法,解决了水色遥感软件SEADAS由于无法计算近岸的二类水体离水辐射率而简单地将其设为0的问题。应用该方法计算出的离水辐射率反演了渤海表层水体的叶绿素浓度,并选取近岸同期监测点的实测值对反演结果进行验证。通过对比反演值与实测值,多数相对误差值均较小于10%,证明了反演结果较为准确,同时反演的叶绿素浓度的空间分布也符合冬季渤海的水团和环流状况。这说明应用改进后的大气校正方法能够很好地用于渤海表层水体的叶绿素浓度反演。

A suitable algorithm of atmospheric correction for case-Ⅱ water in China seacoast is given out to solve the problem that water-leaving radiance of case-Ⅱ water in seacoast is set to 0 by ocean color remote sensing software SEADAS due to calculation inability. Then the chlorophyll concentration of Bohai Sea is retrieved using the water-leaving radiance by the improved method, and choose station monitoring results to validate the retrieved results is chosen at the same time. Comparing the two results, we find that most relative errors are lower than 10%, which proves that the retrieved results are exact. Simultaneously, special distribution of retrieved chlorophyll concentration coincides with the Bohai Sea status of water masses and water circumfluence in winter. This confirms that improved algorithm for atmospheric correction can commendably be used to retrieve the chlorophyll concentration of the Bohai Sea.