水体吸收系数是影响水体光场分布的重要参数,在水色遥感探测中受到广泛关注。本文利用2012年9月辽东湾区域航次调查数据分析该区域水体各组分吸收系数的分布情况,结果表明,辽东湾水体中浮游植物含量相对较高。并利用该航次数据,建立了区域性半分析算法,该算法基于相邻波段间固有光学量的线性关系,首先通过遥感反射率反演得到550 nm波段的水体总吸收系数,再通过后向散射波段相关关系外推得到其他波段的总吸收系数。经独立测试数据检验,3个波段(412、443、550 nm)总吸收系数反演的平均相对误差分别为19.71%,17.99%,9.35%,说明区域性半分析算法能较好地估算研究区域的水体总吸收系数。本文还通过引入随机误差对算法稳定性进行了检验,结果表明算法具有较好的稳定性。
Absorption coefficient is an important parameter that affects the optical field distribution of water, and it has attracted attention widely in the field of ocean color remote sensing. This study analyzed the distribution of the water absorption coefficient with the sea voyage survey data of the Liaodong Bay in September 2012. The analysis results suggest that phytoplankton in water content is relatively high. And this paper also developed a regional semi-analytical algorithm with the survey data. The algorithm was based on the hypothesis of the linear relationship between the inherent optical properties on adjacent bands. The total absorption coefficient at 550 nm is obtained first from remote sensing reflectance, and then extrapolated into other bands using the relationship of backscatter. Compared with the test data, the average relative errors for three wavelengths(412, 443 and 550 nm) are 19.71%, 17.99% and 9.35%, respectively, indicating that the regional algorithm can estimate the total absorption coefficient of the studied area. The stability of the algorithm was tested by adding random errors to the data, and the results showed that the algorithm is stable.