摘要
作为空间目标与地基望远镜红外成像终端间不确知参量之一的地球热辐射,会降低传统双波段比色测温法正向求解准确度.为了提高目标温度估计的准确度,建立了基于红外探测器测量电子数的评价函数,得到了求解最大似然函数的温度反向求解模型;推导了双波段比色测温法的温度正向求解模型,进行了两种测温方法的仿真实验与比较分析.结果表明:目标温度反演准确度与成像探测器信噪比、地球热辐射估算准确度以及波段之间的发射率差异有着紧密的关系;当信噪比较低时,双波段比色测温法会陷入无解区域;当信噪比较高时,双波段比色测温法与最大似然函数法反演温度准确度相当;最大似然函数法采用有约束与有限内存的拟牛顿优化算法可有效避免目标函数陷入局部最小值;最大似然函数法具有很强的抗噪音干扰能力,能扩大目标温度求解的范围,并具有较高的准确度;在保证信噪比的情况下,增加成像波段数目可以提高温度反演准确度.
The earth＇s heat radiation, as one of the unknown parameters between the space target and ground-based telescopes infrared imaging terminal, will reduce the traditional dual-band pyrometry forward accuracy. To improve the accuracy of target temperature estimation, an estimation function based on the measured number of electrons is established, and temperature inversed solution model for solving the maximum likehood function is obtained; dual-band forward solution method based on the number of electrons is derived, and the simulation and analysis of the algorithm is performed. The experimental results indicate that the target temperature inversion precision has a close relationship with the imaging detector signal-to-noise ratio, the earth＇s thermal radiation estimation accuracy and emissivity difference between bands; when the signal-to-noise ratio is relatively low, the dual-band pyrometry is in no solution; when the signal-to-noise ratio is relatively high, the inversion temperature accuracy of the dual-band pyrometry and maximum likelihood function is quite; function method of maximum likelihood using constraints and limited memory quasi-Newton optimization algorithm can effectively avoid the objective function into a local minimum; maximum likelihood function method has a strong ability to resist noise interference, can expand the scope of object temperature solution, and with high precision; under the guarantee of signal-to-noise ratio, increasing the number of image-band in order to improve the accuracy of temperature inversion.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2013年第7期845-848,共4页
Acta Photonica Sinica
基金
国家高技术研究发展计划(No.2012AAXXX1009)资助
关键词
红外测温
比色测温
极大似然估计
蒙特卡罗仿真
Infrared temperature
Color pyrometry
Maximum likelihood estimate
Monte carlo simulation
Color pyrometry
