光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
9期
2665-2671
,共7页
郑峰%刘丽莹%刘小溪%李野%石晓光%张国玉%宦克为
鄭峰%劉麗瑩%劉小溪%李野%石曉光%張國玉%宦剋為
정봉%류려형%류소계%리야%석효광%장국옥%환극위
光谱辐射定标%近红外%中温黑体%辐射传输模型%尺度特征
光譜輻射定標%近紅外%中溫黑體%輻射傳輸模型%呎度特徵
광보복사정표%근홍외%중온흑체%복사전수모형%척도특정
Spectral radiometric calibration%NIR%MTBB%Radiation transfer model%Scale feature
中温黑体是红外谱段常用的高精度辐射标尺设备,而近红外是处于其有效辐射范围边缘的谱段,所以该谱段的定标研究相对较少。研究了基于中温黑体的近红外光纤光谱仪辐射定标方法,主旨是探讨定标精度如何受定标模型的结构参数选择的影响,进而为近红外光谱辐射计量溯源提供技术参考。采用50~1050℃的可调中温黑体对近红外光纤光谱仪(950~1700 nm)进行辐射定标。针对定标的关键环节重点讨论了两个内容,首先是辐射传输模型的几何因子匹配问题,比较分析了传统的双圆盘辐射传输模型和光纤直接耦合模型。对于光纤光谱仪的辐射定标来讲,采用光纤直接耦合形式的辐射传输模型,结构上更简单,耦合效率更高。其次重点分析了辐射定标中模型的结构参数对定标精度的影响,其影响的原因是定标数据本身属性中的尺度结构特征,即通常所说的非线性问题。因此对于定标精度要求较高时,需要采用非线性定标模型进行校正,并尽可能保证测试点采样的尺度均衡,这是小样本数据解释非线性结构关系时无法回避的样本选择问题。数据分析结果表明,定标方程的不同结构参数的选择策略对定标精度有显著影响,校正方程的样本残差标准差带变化范围为±0.1%~±1%。
中溫黑體是紅外譜段常用的高精度輻射標呎設備,而近紅外是處于其有效輻射範圍邊緣的譜段,所以該譜段的定標研究相對較少。研究瞭基于中溫黑體的近紅外光纖光譜儀輻射定標方法,主旨是探討定標精度如何受定標模型的結構參數選擇的影響,進而為近紅外光譜輻射計量溯源提供技術參攷。採用50~1050℃的可調中溫黑體對近紅外光纖光譜儀(950~1700 nm)進行輻射定標。針對定標的關鍵環節重點討論瞭兩箇內容,首先是輻射傳輸模型的幾何因子匹配問題,比較分析瞭傳統的雙圓盤輻射傳輸模型和光纖直接耦閤模型。對于光纖光譜儀的輻射定標來講,採用光纖直接耦閤形式的輻射傳輸模型,結構上更簡單,耦閤效率更高。其次重點分析瞭輻射定標中模型的結構參數對定標精度的影響,其影響的原因是定標數據本身屬性中的呎度結構特徵,即通常所說的非線性問題。因此對于定標精度要求較高時,需要採用非線性定標模型進行校正,併儘可能保證測試點採樣的呎度均衡,這是小樣本數據解釋非線性結構關繫時無法迴避的樣本選擇問題。數據分析結果錶明,定標方程的不同結構參數的選擇策略對定標精度有顯著影響,校正方程的樣本殘差標準差帶變化範圍為±0.1%~±1%。
중온흑체시홍외보단상용적고정도복사표척설비,이근홍외시처우기유효복사범위변연적보단,소이해보단적정표연구상대교소。연구료기우중온흑체적근홍외광섬광보의복사정표방법,주지시탐토정표정도여하수정표모형적결구삼수선택적영향,진이위근홍외광보복사계량소원제공기술삼고。채용50~1050℃적가조중온흑체대근홍외광섬광보의(950~1700 nm)진행복사정표。침대정표적관건배절중점토론료량개내용,수선시복사전수모형적궤하인자필배문제,비교분석료전통적쌍원반복사전수모형화광섬직접우합모형。대우광섬광보의적복사정표래강,채용광섬직접우합형식적복사전수모형,결구상경간단,우합효솔경고。기차중점분석료복사정표중모형적결구삼수대정표정도적영향,기영향적원인시정표수거본신속성중적척도결구특정,즉통상소설적비선성문제。인차대우정표정도요구교고시,수요채용비선성정표모형진행교정,병진가능보증측시점채양적척도균형,저시소양본수거해석비선성결구관계시무법회피적양본선택문제。수거분석결과표명,정표방정적불동결구삼수적선택책략대정표정도유현저영향,교정방정적양본잔차표준차대변화범위위±0.1%~±1%。
The medium temperature black body (MTBB)is conventional high precision equipment used as spectral radiometric scale in infrared spectral region.However,in near-infrared (NIR)spectral region,there are few papers about spectral radiomet-ric calibration by using MTBB,that is because NIR spectral region is the borderland of its effective spectral region.The main re-search of this paper is spectral radiometric calibration method by using MTBB in NIR spectral region.Accordingly,this paper is devoted mostly to a discussion of how the calibration precision could be affected by selecting different structural parameters of calibration model.The purpose of this paper is to present the results of research and provide technical reference for improving the traceability in NIR spectral radiometric calibration.In this paper,a NIR fiber coupled spectrometer,whose wavelength range covers from 950 to 1 700 nm,has been calibrated by a MTBB with adjustable temperature range from 50 to 1 050 ℃.Concentra-ting on calibration process,two key points have been discussed.For one thing,the geometric factors of radiation transfer model of the calibration systems have been compared between traditional structure and fiber direct-coupled structure.Because the fiber direct-coupled model is simple and effective,it has been selected instead of traditional model based on the radiation transfer be-tween two coaxial discs.So,it is an advantaged radiation transfer model for radiometric calibration of fiber coupled spectrome-ter.For another thing,the relation between calibration accuracy and structural parameters of calibration model has been analyzed intensively.The root cause is scale feature of attribute of calibration data itself,which is the nonlinear structure in scales of spec-tral data.So,the high precision calibration needs nonlinear calibration model,and the uniform sampling for scale feature is also very important.Selecting sample is an inevitable problem when the nonlinear model is explained by small sample dataset.As the analytic results,there are obviously influences for the calibration precision among different strategies of selecting model’s struc-tural parameters.The calibration precision,which is mathematical described by standard deviation of spectral data for calibra-tion,could be from ±0.1% to ±1%.