收稿日期: 2009-01-12
修回日期: 2009-04-07
网络出版日期: 2009-10-10
基金资助
863计划项目(2006AA09A302,2008AA09Z108);国家自然科学基金项目(40521003)
An evaluation of two semi-analytical ocean color algorithms for waters off South China
Received date: 2009-01-12
Revised date: 2009-04-07
Online published: 2009-10-10
Supported by
863计划项目(2006AA09A302,2008AA09Z108);国家自然科学基金项目(40521003)
本文基于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443 nm的总吸收系数(a443 ),南海的对数均方根误差(RMSE )为0.046,平均相对误差为7.9%,对数平均偏差为0;福建沿岸水体的对数均方根误差(RMSE )为0.194,平均相对误差为30.6%,对数平均偏差为-0.167 。GSM算法在两类水体的反演成效类似,A443 之RMSE和平均相对误差,南海分别为0.161和27.7%,福建沿岸分别为0.149和32.1%,但从A443的对数平均偏差值看,其在南海反演值低于实测值(对数平均偏差为-0.142 ),在福建沿岸则略呈高于实测值(对数平均偏差为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。
汪文琦 , 董强 , 商少凌 , 吴璟瑜 , 李忠平 . 基于两种半分析算法的水体吸收系数反演[J]. 热带海洋学报, 2009 , 28(5) : 35 -42 . DOI: 10.11978/j.issn.1009-5470.2009.05.035
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) in different seasons, the performance of the Quasi-Analytical Algorithm (QAA) and the Garver-Siegel-Maritorena (GSM) algorithm for water’s absorption coefficients are evaluated. It is found that the retrieval performance of the two algorithms is similar as those by other researchers performed in different regions. To waters in this study, QAA performed better in the South China Sea than for waters off Fujian coast. For total absorption coefficient at 443 nm (a443), the root-mean-square-error (RMSE) is 0.046 in the South China Sea, with an averaged percentage error of 7.9%, and averaged error in log scale (δ) close to 0. For coastal waters off Fujian, RMSE, an averaged percentage error and δ are 0.194, 30.6%, and -0.167, respectively. The performance of GSM is similar for the two regions of waters. For a443, RMSE and an averaged percentage error are 0.161 and 27.7% in the South China Sea, respectively; and are 0.149 and 32.1% for waters off Fujian coast. Their δ values, however, are negative (-0.142, indicating underestimation) in the South China Sea, and positive (0.016, indicating slight overestimation) in coastal waters off Fujian. Further analysis indicate that the differences between the empirical parameters employed in the algorithms and actual values of the waters under study are the main reasons causing errors in remote sensing retrievals, and it is necessary to regionally refine those parameters in order to improve the algorithm performances.wei
[1] PREISENDORFER R W. A survey of theoretical hydrologic optics[J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 1968, 8(1): 325—338.
[2] BEHRENFELD M J, O'MALLEY R T, SIEGEL D A, et al. Climate-driven trends in contemporary ocean productivity[J]. Nature, 2006, 444(7120): 752—755.
[3] LEE Z P. Remote sensing of inherent optical properties: Fundamentals,tests of algorithms, and applications[M]. Dartmouth, Canada: International Ocean-Colour Coordinating Group, 2006:73—93.
[4] LEE Z P, CARDER K L, AMONE R A. Deriving inherent optical properties from water color: A multiband quasi-analytical algorithm for optically deep waters[J]. Applied Optics, 2002, 41(27): 5755—5772.
[5] LEE Z P, WEIDEMANN A, KINDLE J, et al. Euphotic zone depth: Its derivation and implication to ocean-color remote sensing[J]. Journal of Geophysical Research-Oceans, 2007, 112(C03009): doi:10.1029/2006JC003802.
[6] GARVER S A, SIEGEL D A. Inherent optical property inversion of ocean color spectra and its biogeochemical interpretation Ⅰ. Time series from the Sargasso Sea[J]. Journal of Geophysical Research-Oceans, 1997, 102(C8): 18607—18625.
[7] MARITORENA S, SIEGEL D A, PETERSON A R. Optimization of a semi-analytical ocean color model for global-scale applications[J]. Applied Optics, 2002, 41(15): 2705—2714.
[8] HOOKER S B, CENTER G S F. The SeaWiFS Bio-optical Archive and Storage System (SeaBASS), Part Ⅰ. National Aeronautics and Space Administration[M].Goddard Space Flight Center; National Technical Information Service, 1994:40.
[9] MELIN F, ZIBORDI G, BERTHON J F. Assessment of satellite ocean color products at a coastal site[J]. Remote Sensing of Environment, 2007, 110(2): 192—215.
[10]WU JINGYU, HONG HUASHENG, SHANG SHAOLING, et al. Variation of phytoplankton absorption coefficients in the northern South China Sea during spring and autumn[J]. Biogeosciences Discussions, 2007, 4: 1555—1584.
[11] FARGION G S, MUELLER J L. Ocean optics protocols for satellite ocean color sensor validation, Revision 3 [R].NASA/TM-2002-21004,2002.
[12] MOBLEY C D. Estimation of the remote-sensing reflectance from above-surface measurements[J]. Applied Optics, 1999, 38: 7442—7455
[13] 李铜基, 唐军武, 陈清莲, 等. 光谱仪测量离水辐射率的处理方法[J]. 海洋技术, 2000, 19(3): 11—16.
[14] 唐军武, 田国良, 汪小勇, 等. 水体光谱测量与分析Ⅰ: 水面以上测量法[J]. 遥感学报, 2004, 8(1): 37—44.
[15] 隋晓飞, 商少平, 马晓鑫, 等. 剖面法与水面之上法测量水面下遥感反射率的比较[J]. 厦门大学学报(自然科学版), 2007, 46(S1): 6—11.
[16] MITCHELL B, G, BRICAUD A, CARDER K. Determination of spectral absorption coefficients of particles, dissolved material and phytoplankton for discrete water samples[R]//FARGION G S, MUELLER J L. Ocean Optics Protocols For Satellite Ocean Color Sensor Validation, Revision 2. Greenbelt, Maryland: NASA Goddard Space Flight Space Center, 2000:125—153.
[17] CLEVELAND J S, WEIDEMANN A D. Quantifying absorption by aquatic particles: a multiple scattering correction for glass-fiber filters[J]. Limnology and Oceanography, 1993, 38(6): 1321—1327.
[18] 吴璟瑜. 中国东南近海光吸收特性研究[D]. 厦门: 厦门大学, 2006.
[19] HONG HUASHENG, WU JINGYU, SHANG SHAOLING, et al. Absorption and fluorescence of chromophoric dissolved organic matter in the Pearl River Estuary, South China[J]. Marine Chemistry, 2005, 97(1—2): 78—89.
[20] BRICAUD A, MOREL A, BABIN M, et al. Variations of light absorption by suspended particles with chlorophyll a concentration in oceanic (case Ⅰ) waters: Analysis and implications for bio-optical models[J]. Journal of Geophysical Research-Oceans, 1998, 103(C13): 31033—31044.
[21] MOREL A. Optical modeling of the upper ocean in relation to its biogenous matter content (case I waters)[J]. Journal of Geophysical Research Oceans, 1988, 93(C9): 10749—10768.
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