遥感信息
遙感信息
요감신식
2014年
4期
112-125
,共14页
申茜%李俊生%吴远峰%张兵
申茜%李俊生%吳遠峰%張兵
신천%리준생%오원봉%장병
固有光学量%光谱拟合%吸收系数%散射系数%湖泊水体
固有光學量%光譜擬閤%吸收繫數%散射繫數%湖泊水體
고유광학량%광보의합%흡수계수%산사계수%호박수체
inherent optical parameter%spectral curve fitting%absorption coefficient%scattering coefficient%lake
固有光学量描述了水体的吸收、散射等光学特性,随波长变化而呈现出连续的光谱。固有光学量光谱拟合不仅简化了固有光学量的表达,便于代入水质参数反演的解析模型或是代入模拟水体辐射场的正向模型中去;还有助于利用拟合得到的参量定量地对比不同水体的固有光学特性。本文从非藻类颗粒物吸收系数光谱、有色溶解性有机物吸收系数光谱、浮游植物吸收系数光谱、总颗粒物体散射函数光谱及后向散射系数光谱4个方面出发,归纳了国内外湖泊水体固有光学量光谱数据拟合方法,同时对比了以往文献中的拟合得到的参量,进一步分析总结了这些参量与色素成分、化学组成、细胞粒径、浑浊程度等水体状况的内在关系,并给出了近几年内出现的一些前沿方向。在4类固有光学量中,当前最常用且最被认可的是有色溶解性有机物吸收光谱的拟合,拟合结果常被直接代入到生物光学模型中去。在拟合光谱时,需要更多地重视选用的参考波长、光谱范围、模型类别等拟合方法。拟合非藻类颗粒物吸收光谱、有色溶解性有机物吸收光谱时,建议采用负指数模型而不是取对数后的线性形式模型;采用指数模型拟合浮游植物吸收光谱与叶绿素 a 浓度的关系时,选择675nm 为参考波长要优于选择443nm。在拟合总颗粒物后向散射光谱时,常采用负指数模型或双曲线模型,其中双曲线模型被采用的较多。体散射函数β(ψ0,λ)随波长变化的光谱形状不都相似,有些会在色素吸收特征波长处表现出峰值特征,有些随波长向长波方向移动而递减。本文成果将有助于促进湖泊水体固有光学量的分析与应用。
固有光學量描述瞭水體的吸收、散射等光學特性,隨波長變化而呈現齣連續的光譜。固有光學量光譜擬閤不僅簡化瞭固有光學量的錶達,便于代入水質參數反縯的解析模型或是代入模擬水體輻射場的正嚮模型中去;還有助于利用擬閤得到的參量定量地對比不同水體的固有光學特性。本文從非藻類顆粒物吸收繫數光譜、有色溶解性有機物吸收繫數光譜、浮遊植物吸收繫數光譜、總顆粒物體散射函數光譜及後嚮散射繫數光譜4箇方麵齣髮,歸納瞭國內外湖泊水體固有光學量光譜數據擬閤方法,同時對比瞭以往文獻中的擬閤得到的參量,進一步分析總結瞭這些參量與色素成分、化學組成、細胞粒徑、渾濁程度等水體狀況的內在關繫,併給齣瞭近幾年內齣現的一些前沿方嚮。在4類固有光學量中,噹前最常用且最被認可的是有色溶解性有機物吸收光譜的擬閤,擬閤結果常被直接代入到生物光學模型中去。在擬閤光譜時,需要更多地重視選用的參攷波長、光譜範圍、模型類彆等擬閤方法。擬閤非藻類顆粒物吸收光譜、有色溶解性有機物吸收光譜時,建議採用負指數模型而不是取對數後的線性形式模型;採用指數模型擬閤浮遊植物吸收光譜與葉綠素 a 濃度的關繫時,選擇675nm 為參攷波長要優于選擇443nm。在擬閤總顆粒物後嚮散射光譜時,常採用負指數模型或雙麯線模型,其中雙麯線模型被採用的較多。體散射函數β(ψ0,λ)隨波長變化的光譜形狀不都相似,有些會在色素吸收特徵波長處錶現齣峰值特徵,有些隨波長嚮長波方嚮移動而遞減。本文成果將有助于促進湖泊水體固有光學量的分析與應用。
고유광학량묘술료수체적흡수、산사등광학특성,수파장변화이정현출련속적광보。고유광학량광보의합불부간화료고유광학량적표체,편우대입수질삼수반연적해석모형혹시대입모의수체복사장적정향모형중거;환유조우이용의합득도적삼량정량지대비불동수체적고유광학특성。본문종비조류과립물흡수계수광보、유색용해성유궤물흡수계수광보、부유식물흡수계수광보、총과립물체산사함수광보급후향산사계수광보4개방면출발,귀납료국내외호박수체고유광학량광보수거의합방법,동시대비료이왕문헌중적의합득도적삼량,진일보분석총결료저사삼량여색소성분、화학조성、세포립경、혼탁정도등수체상황적내재관계,병급출료근궤년내출현적일사전연방향。재4류고유광학량중,당전최상용차최피인가적시유색용해성유궤물흡수광보적의합,의합결과상피직접대입도생물광학모형중거。재의합광보시,수요경다지중시선용적삼고파장、광보범위、모형유별등의합방법。의합비조류과립물흡수광보、유색용해성유궤물흡수광보시,건의채용부지수모형이불시취대수후적선성형식모형;채용지수모형의합부유식물흡수광보여협록소 a 농도적관계시,선택675nm 위삼고파장요우우선택443nm。재의합총과립물후향산사광보시,상채용부지수모형혹쌍곡선모형,기중쌍곡선모형피채용적교다。체산사함수β(ψ0,λ)수파장변화적광보형상불도상사,유사회재색소흡수특정파장처표현출봉치특정,유사수파장향장파방향이동이체감。본문성과장유조우촉진호박수체고유광학량적분석여응용。
Inherent optical parameters (IOPs)describe the optical properties of water,including absorption and scattering properties,which are always continuous spectra versus wavelength.Spectra curves fitting for IOPs not only simplify the expression but also is beneficial to compare quantitatively IOPs in different waters via fitting variables,which is easier to be substituted into semi-analytic models to retrieve water quality parameters or into forward models to simulate radiance distribution in water.This paper introduces absorption spectra of non-algae particles,color dissolved organic matters and phytoplankton,volume scattering function and backscattering spectra of total particles.In this paper,the spectral curve fitting methods for IOPs in lakes of China and abroad are summarized,and the variables from fitting methods are compared with those in published literature.Furthermore,the paper discusses the relationships between these variables and water body status such as pigments,chemical composition,cell size and turbidity.Several related forefront directions are claimed.During four types of IOPs,the most recognized and frequently used is curves fitting for absorption spectra of color dissolved organic matters,which is always substituted into the bio-optical model directly.The reference wavelength,wavelength range and model type should be paid much more attention in spectral curve fitting.In spectra curve fitting for absorption of non-algae particles and color dissolved organic matter,it is recommended to use negative exponential model but not linear model after the logarithm.Another recommendation is to use 675nm,not 443nm as reference wavelength when using exponential model to fit the relationship between phytoplankton absorption and chlorophyll a concentration.For total particles backscattering,negative exponential model and hyperbolic model are usually used.The latter is used mostly.The shapes of volume scattering function β(ψ0,λ)are not always the same.In them,some show peaks at the wavelengths where absorption characteristics of pigments are,and others reduce gradually when wavelength move towards long wave.This paper will be conducive to accelerate analysis and application of IOPs in lakes.