洛伦兹光谱线型的高层大气风场被动探测原理分析

通过探测高层大气中气辉(极光)辐射线的多普勒频移,可以反演出高层大气中的速度、温度和压强等物理量。以高层大气中的极光(原子氧跃迁所辐射的两条主要谱线)为被探测源,对于洛伦兹光谱线型高层大气风场的探测原理和方法进行了研究;给出了基于洛伦兹光谱线型高层大气的速度场、温度场和压力场的分布规律和理论计算公式;采用计算机模拟,描绘了洛伦兹光谱线型风场的误差曲线,表明了洛伦兹光谱线型在高层大气风场探测中占有相当重要的地位。     

电磁学多普勒效应在高层大气探测中的应用

风是理解大气动力学行为、热力学性质和成分结构的一个关键参数,大气风场的探测已成为当今国际上的前沿科学和热门研究课题.高层大气(80～300 km)风场被动探测的基础理论是干涉成像技术和电磁波的多普勒效应.论文对气辉(极光)的形成、电磁波的多普勒效应和双光束干涉进行了解释;对通过探测目标气辉谱线的多普勒频移,获知大气风场的速度、温度和粒子辐射率的原理进行了论述;给出了由于频移量数值极小难以观测、进而将频移量的观测转换成对位相、干涉图观测的四强度探测理论.向读者展示了电磁学、光学的基本原理应用到当今高新科技中的巧妙与完美,启发对物理学基本知识应用和对科学家创新思维的联想和思考.     

偏振风成像干涉仪多波长探测理论研究

简述了偏振风成像干涉仪(PAMI)探测高层大气风场的基本原理;研究得出了多波长探测时偏振风成像干涉仪干涉强度、仪器调制度与位相延迟片的延迟位相之间的理论表达式;得出了偏振风成像干涉仪的干涉强度和仪器调制度受所探测谱线波长调制的重要结论;采用计算机模拟分析了使用偏振风成像干涉仪(设计谱线为高层大气氧原子跃迁时辐射的630nm的极光谱线)探测高层大气时各目标谱线的干涉强度和仪器调制度,给出了干涉强度和仪器调制度与探测谱线波长之间的关系,得出了732nm的极光谱线不适合用作探测目标的结论. 本文为高层大气风场探 关键词： 高层大气风场探测 偏振风成像干涉仪 调制度 多波长探测     

高层大气风场四强度测量法误差分析与计算

利用干涉成像光谱技术和电磁波的多普勒效应,通过测量高层大气(80—300km)中的气辉(极光)辐射线的四个干涉强度值而获知高层大气的速度和温度信息.采用四强度干涉测量法,分别对基于Michelson干涉仪的动镜扫描和基于无动镜四分区镀膜的干涉图获取模式所引起的测量误差进行了深入的理论分析与研究.给出了由于此测量误差所导致的相位误差所引起的高层大气风场速度、温度的误差数值;采用计算机模拟得出了在不同相位误差条件下,两种模式计算得到的风场速度和温度的误差分布图;给出了风速误差、温度误差与相位步进误差的关系曲线 关键词： 高层大气风场测量 四强度测量法 模拟计算     

光学学报 2005年25卷 学科分类索引

文题期数起始页大气与海洋光学差分吸收激光雷达回波信号统计模型的研究1 1海洋水色及水温扫描仪精确瑞利散射计算2 145跟踪抖动对激光湍流大气传输光束扩展的影响2 152米氏散射激光雷达近场距离校正函数曲线拟合法修正3 289高斯波束在湍流大气斜程传输中的闪烁问题研究4 433洛伦兹光谱线型的高层大气风场被动探测原理分析5 577相干激光雷达距离像的噪声抑制算法研究5 581基于洛伦兹线型极光的上层大气风场探测模式研究6 721空间激光通信中光强起伏尺度特征的数值分析8 1009圆芯型边孔光纤双折射的有限元分析8 1013差分吸收光谱法测量空气中…     

高层大气风场四强度测量法误差分析与计算

利用干涉成像光谱技术和电磁波的多普勒效应，通过测量高层大气(80—300km)中的气辉(极光)辐射线的四个干涉强度值而获知高层大气的速度和温度信息.采用四强度干涉测量法，分别对基于Michelson干涉仪的动镜扫描和基于无动镜四分区镀膜的干涉图获取模式所引起的测量误差进行了深入的理论分析与研究.给出了由于此测量误差所导致的相位误差所引起的高层大气风场速度、温度的误差数值；采用计算机模拟得出了在不同相位误差条件下，两种模式计算得到的风场速度和温度的误差分布图；给出了风速误差、温度误差与相位步进误差的关系曲线     

高层大气被动探测技术

简要介绍了高层大气被动探测技术的研究历史、现状和发展趋势.论述了高层大气被动探测技术的基本原理和方法,给出了高层大气被动探测的辐射源和气辉谱线、四强度探测法和临边探测模式.重点介绍了自行设计研制的风成像干涉仪的宽场、消色差、温度补偿理论以及工程设计和研制.采用风成像干涉仪进行了模拟高层大气探测实验,给出了高层大气风场、...     

佛克脱光谱线型干涉图的理论及其应用研究

在一般压强的条件下,佛克脱光谱线型(高斯光谱线型和洛伦兹光谱线型的卷积)是最接近实际的光谱线型,但由于其没有具体的表达式,所以在实际应用中常采用各种近似来表示佛克脱光谱线型。文章未采用任何近似,计算了佛克脱光谱线型干涉图的具体表达式,表明虽然佛克脱光谱线型没有具体表达式,但其干涉图是可以严格求解的。而且其变换结果为一实函数,与高斯光谱线型和洛伦兹光谱线型的变换结果的表达式非常相似,因而可以进行谱线综合展宽的各种计算,而不是像有的文献所预言的有实部和虚部两部分,给计算带来困难。计算结果与实验结果一致。作为应用的一个实例,作者指出了其在大气风场测量中的重要应用。此计算对气体展宽在傅里叶变换光谱仪中的应用方面具有非常重要的意义。     

基于洛伦兹线型极光的上层大气风场探测模式研究

从洛伦兹线型极光的干涉强度、调制度与光程差的理论公式出发,用λ/4的步进光程差即“四强度法”获得一个波长范围内的4个干涉强度值,以实现基于洛伦兹线型极光的上层大气的风速、温度、压强等物理量的探测。提出用改形萨尼亚克成像干涉仪替代迈克耳孙干涉仪实现上层大气风场,给出了基准光程差的公式,并用四面角锥棱镜镀膜技术获得4个干涉强度值来同时探测上层大气风场的模式。最后在实验室将Kr灯557.0nm调整光束到一定宽度,对称地从顶角为60°的两面镀膜角锥棱镜的顶点入射,用768pixel×576pixel的CCD照相机接收到两个光斑的成像,这两个光斑的再复制就得到镀膜四面角锥棱镜在一个周期内的4个干涉强度光斑,从而获得上层大气风场。     

新型风成像干涉仪温度补偿理论研究

简述了高层大气风场被动式遥感探测的基本原理;论述了新型风成像干涉仪宽场、消色差、温度补偿理论,针对目前国际上采用的风成像干涉仪补偿方法的不足,从理论上进行了分析与讨论,给出了四层介质的优化补偿理论和方案.模拟结果表明,该补偿可完全理想地消去单色光的温差,且复色光的温差补偿要比现有的方法提高1—2个量级.该研究为设计宽场、消色差、温度补偿的新型风成像干涉仪和提高风场探测精度提供了重要的理论依据和实践指导.     

Principle of temperature,velocity and pressure of upper atmospheric wind measurement for the Voigt profile

Using the accurate expression of the Fourier transform of the pure Voigt spectral line profile, we present the principle of the passive optical method to measure temperature, velocity, and pressure of atmospheric wind for the Voigt profile. Through discussion, from the Gaussian, Lorentzian and Voigt profiles, we find that velocity will not be affected, pressure can be derived for Lorentzian and Voigt profiles, and temperature will be affected greatly. By simulation and comparison, we find that temperature derived from the Voigt profile is greater than that from the Gaussian profile, and it is less than that from the Lorentzian profile. This discussion will be significant in accurate upper atmospheric wind measurement.     

Interference image spectroscopy for upper atmospheric wind field measurement

Based on the observation of natural airglow and auroral visible emission lines in the upper atmosphere as the explored source, we have surveyed the upper atmosphere wind field through interference imaging spectroscopy coupled with the Doppler effect of electrical and magnetic waves. The velocity and temperature of the upper atmospheric wind field are analyzed and studied. The survey theory and calculation formula of atmosphere wind field in all directions and multi-directions are presented when the relative velocity of the explored source to the detector and their linking line have an arbitrary angle. We also analyzed the effects of the measurement of the upper atmospheric wind field using computer simulation, and explained the reason why the auroral emission line is thought as Gaussian profile.     

利用干涉成像光谱技术测量大气风场

以大层大气中的气辉（极光）为被探测源,利用干涉成像光谱技术和电磁波的多普勒效应对上层大气风场进行测量,分析和计算了大气风场的速度和温度,并就被探测源和探测器之间的相对速度与其连线成任意角时的情形进行了讨论。采用计算机模拟,分析了大气风场的测量效果。     

The influences of the wavelength bandwidth on the measured wind velocity and temperature in the static polarization wind imaging interferometer

The static polarization wind imaging interferometer (SPWII) is a device used to measure wind velocity and temperature of the upper atmosphere. In this paper, the principle of SPWII is expounded. Using the four-side pyramid prism and polarizer array, four intensity interferograms of different phase differences form on the four subareas of the CCD which is located at the focal plane of the imaging lens. The wind velocity and temperature can be derived from the interferograms. Using the approximation and the antitheses, we analyze the influences of the wavelength bandwidth on the measured wind velocity and atmospheric temperature. According to the design requirements of the SPWII, the errors of the wind velocity and the atmospheric temperature are less than 5 m/s and 5 K when the incident wavelength bandwidth is in the range of [?3.08, 3.08] nm. The range is estimated and verified by simulations. These results are helpful for the realization and data processing of the SPWII.     

Formation of spectral lines in planetary atmospheres—V. Collision narrowed profiles of quadrupole lines in hydrogen atmospheres

The interpretation of a hydrogen quadrupole spectrum is complicated by the collision narrowing phenomenon exhibited by these lines. The profile must be accurately computed for use within any interpretative technique since the spectroscopic features of line profile and center to limb variation of the equivalent width are sensitive to the quadrupole line shape.The Dicke profile, which assumes that the quadrupole line shape is Lorentzian with a half-width that varies inversely as the pressure has been suggested as a simple alternative to the Galatry profile. In this paper, we present comparisons of the line profile, equivalent width and center-to-limb variation of the equivalent width of quadrupole lines for a characteristic scattering and nonscattering hydrogen atmosphere, where the line profile has been computed by the Dicke and Galatry shapes. Our computations show that the results produced by the Dicke profile may be very different from the features predicted by the Galatry profile, which has been shown to give results in good agreement with experiment.We therefore conclude that it is invalid to use the Dicke approximation for computing collision-narrowed profiles of hydrogen quadrupole lines at visible and near infrared spectroscopic wavelengths in any hydrogen atmosphere.     

Study of a lidar for measurement of thermospheric He I 1083 nm for Lorentzian profile

Using the lidar backscatter cross-section and the normalized Lorentzian profile, we investigate the backscatter cross-section and the returned signal of He I 1083 nm for the Lorentzian profile theoretically. Taking the average temperature and pressure, we find that the backscattering cross-section for Lorentzian profile is larger than that for Gaussian profile near the line center, while is smaller than that for Gaussian profile far away from the line center. Through simulation, we find that the returned signal is strong enough for measurement of thermospheric metastable helium. This investigation is significant in the thermospheric metastable helium by lidar.     

温度和压强的变化对谱线线型峰值的影响

谱线线型是用于气体浓度测量中的一个重要参数。本文基于温度(压强)变化会引起相应压强(温度)的变化这一点,考虑温度和压强同时变化对气体线型峰值的影响。通过分析氟化氢的吸收谱线,发现可用Lorentzian线型来计算峰值吸收系数的温度和压强范围都扩大,而Gaussian线型在绝大数情况下不能用来计算峰值吸收系数;在一定的温度范围和压强范围内,如果只考虑压强或温度的变化,由此计算的三种线型峰值(Gaussian,Lorentzian和Voigt)的相对误差大于0.1。因此,在计算线型峰值时,需考虑压强和温度同时变化对线型峰值的影响。最后分别讨论了甲烷、二氧化碳、一氧化碳及一氧化氮,得到与氟化氢结论相似的结论,结论的不完全相同是由于每种气体在波数、压力展宽系数、相对分子质量及温度系数上的不同而导致。