摘要
为充分校正红外探测器响应非线性,解决大动态范围下使用多点法定标出现的温度点数冗余的问题,提出一种基于相对标准差阈值划分的定标温度点选择方法。使用标准差法将响应曲线划分为多段,采用最小二乘法线性拟合得出定标系数,并通过数据反演、合并和压缩,获得红外光谱成像仪各个谱段最终定标温度点。仿真结果表明,对于模拟的单光谱通道探测器非线性响应,相同划分条件下(相对标准差1%),对比常规二分法,所提方法可将温度点数由22个降低至14个;相同温度点数条件下(20个),对比均匀划分,所提方法可将非线性度最大值由1.06%降低至0.40%。对于模拟的17个光谱通道,取10个定标温度点时,非线性度均值小于1%。红外相机实测实验结果表明,利用该方法确定的定标温度点,定标后非线性度均值达到0.48%。该方法可有效减少定标温度点数,降低载荷在轨定标资源要求。
In order to adequately correct the response nonlinearity of infrared detectors,the multi-point method is often used to replace the traditional two-point method for the radiometric correction of satellite-borne infrared spectral imagers,and the number of required calibration temperature points increases with the increase of the dynamic range.Aiming at the redundancy of temperature points in multi-point calibration,a calibration temperature point selection method based on relative standard deviation threshold division is proposed.Firstly,the experimentally obtained instrumental response curve is divided into multiple segments using the standard deviation method,and each segment is linearly fitted using the least-squares method to ensure the fitting accuracy;secondly,the calibration coefficients derived from the fitting are inversely performed to determine the blackbody temperature points for two-point calibration in each segment.The same method is used to divide the nonlinear response curves within all spectral segments,and the corresponding calibrated temperature points for all sub-segments of each segment after division are found.Finally,all the temperature points are combined and compressed to determine the final calibration temperature points.In order to verify the feasibility of the method,simulation experiments and real experiments were carried out respectively.The nonlinear response of a single spectral band was simulated,and the standard deviation method and the bisection method were used to divide multiple bands under the same division conditions(relative standard deviation of 1%),and the least-squares method was used for linear fitting after division,resulting in the need for 14 calibrated temperature points after the division of the standard deviation method and the need for 22 calibrated temperature points after the bisection method,and the degree of nonlinearity of the two methods after the division of the fit was less than 1%.It can be proved that the standard deviation method can reduce the number of
作者
王燕恒
李芸
于粲
高翔宇
王爽
WANG Yanheng;LI Yun;YU Can;GAO Xiangyu;WANG Shuang(Key Laboratory of Spectral Imaging Technology,Xi'an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi'an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2024年第11期167-179,共13页
Acta Photonica Sinica
基金
国家自然科学基金(No.61905257)。
关键词
红外光谱成像仪
黑体定标
温度点选择
标准差法
响应非线性
多点定标
Infrared spectral imager
Blackbody calibration
Temperature point selection
Standard deviation method
Response nonlinearity
Multipoint calibration
