基于两种半分析算法的水体吸收系数反演  

An evaluation of two semi-analytical ocean color algorithms for waters of the South China Sea

作　　者：汪文琦[1] 董强[1] 商少凌[1] 吴璟瑜[1] 李忠平 

机构地区：[1]福建省教育部共建海洋环境科学联合重点实验室(厦门大学、福建海洋研究所),福建厦门361005 [2]Northern Gulf Institute, Mississippi State University, MS 39529

出　　处：《热带海洋学报》2009年第5期35-42,共8页Journal of Tropical Oceanography

基　　金：863计划项目(2006AA09A302,2008AA09Z108);国家自然科学基金项目(40521003)

摘　　要：基于42组不同年份不同季节获得的遥感反射率、水体各组分吸收系数的实测数据,对QAA(Quasi-Analytical Algorithm)和GSM(Garver-Siegel-Maritorena)算法在寡营养的南海和富营养的福建沿岸两种不同类型水体的吸收系数反演进行了检验。以水样测量值为参考,两种算法在本研究水体中的反演成效与他人在其它水域的研究结果相当。QAA算法在南海的反演成效高于福建沿岸水体。对于443nm的总吸收系数a(443),南海的对数均方根误差RMSE为0.044,平均相对误差ε为7.9%,对数平均偏差δ为0;福建沿岸水体RMSE=0.190,ε=30.6%,δ=-0.167。GSM算法在两类水体的反演成效类似,a(443)之RMSE和ε,南海分别为0.156和27.7%,福建沿岸分别为0.146和32.1%;但从a(443)的δ值看,其在南海反演值低于实测值(δ=-0.142),在福建沿岸则略呈高于实测值(δ=0.016)。两种算法中的部分经验参数与实测值之间的差异是产生反演误差的主要原因,为了提高反演精度,对算法中经验参数的更进一步区域化调整可能是必要的。With 42 in situ measurements of remote sensing reflectance and component absorption coefficients taken in the South China Sea and coastal waters off Fujian, China during different seasons, the authors evaluate the performance of the Quasi-Analytical Algorithm （QAA） and the Garver-Siegel-Maritorena （GSM） algorithm for water absorption coefficients. It is found that the retrieval performances of the two algorithms are similar to those of the algorithms by other researchers conducted in other regions. In this study, QAA performs better in the South China Sea than in the waters off coastal Fujian. For the total absorption coefficient at 443 nm a（443）, the rootmean-square error （RMSE） is 0.046 in the South China Sea, with an averaged percentage error （ε） of 7.9%, and averaged error in log scale （δ） close to 0. For the waters off coastal Fujian, RMSE, ε and δ are 0.194, 30.6%, and -0.167, respectively. The performance of the GSM is similar for the two waters. For a（443）, RMSE and are 0.161 and 27.7% in the South China Sea and 0.149 and 32.1% in the waters off coastal Fujian, respectively; their δ values, however, are negative （-0.142; indicating underestimation） in the South China Sea and positive （0.016; indicating slight overestimation）in the waters off coastal Fujian. Further analysis indicates that the differences between the empirical parameters employed in the algorithms and actual values of the studied waters are the main reasons causing the errors in remote sensing retrievals, therefore, it is necessary to regionally refine those parameters in order to improve the algorithm performance.

关 键 词：半分析算法 吸收系数 南海 福建沿岸 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]