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1.
才啟胜  黄旻  韩炜  丛麟骁  路向宁 《物理学报》2017,66(16):160702-160702
提出了一种新型的基于Savart偏光镜的外差式偏振干涉成像光谱技术,该技术在偏振干涉成像光谱仪中引入一对平行偏振光栅对,使其得到的干涉图频率与波数相关,具有了波数外差的特点,降低了干涉图频率,从而可利用较少的采样点数实现很高的光谱分辨率.对外差式偏振干涉成像光谱技术的基本原理进行了研究,详细分析了系统光程差、干涉图表达式、光谱分辨率以及光谱复原方法等.最后给出了外差式偏振干涉成像光谱仪的设计实例并进行了计算机仿真模拟,所复原的光谱与输入光谱曲线相符合,验证了方案的正确性.外差式偏振干涉成像光谱仪具有结构紧凑、光通量高、稳定性强、光谱分辨率高的特点,尤其适合超小型高稳定性、高探测灵敏度的高光谱探测应用.  相似文献   

2.
光谱偏振成像技术可同步测量目标的空间信息、光谱成分和偏振特性分量,在天文物理研究、大气成分的探测和生物医学等领域具有巨大的发展潜力。偏振信息的同步获取通常牺牲光谱成像的空间分辨率,为避免光谱成像空间分辨率的降低,提出基于双通道剪切干涉的高光谱偏振成像方法。利用双矩形干涉器实现双通道剪切干涉,两个通道分别进行高分辨率干涉光谱成像以及基于微偏振阵列的光谱偏振成像。分析了双通道剪切干涉以及基于微偏振阵列调制的傅里叶变换光谱偏振成像原理,论述了光谱信息反演方法以及偏振信息提取方法。搭建了实验装置,对实际场景目标进行光谱偏振成像实验,获得了目标的高空间分辨率光谱图像和偏振分量信息。研究表明,该高光谱偏振成像技术可同步进行偏振成像测量和高分辨率光谱成像测量。  相似文献   

3.
为了抑制背景噪声,获得高信噪比的纯干涉条纹并实现图像、光谱和全偏振信息的同时测量,提出了一种基于双强度调制的静态傅里叶变换偏振成像光谱技术新方案.系统由前置望远系统、两个相位延迟器构成的偏振来谱调制模块、Wollaston棱镜构成的偏振.分束器、Savart偏光镜和线偏振器构成的干涉糢块以及CCD面阵探测器组成,可在单一探测器上同时获取两幅经过不同强度调制的全偏振干涉图,通过对两幅全偏振干涉图的简单加减运算,便可获得探测目标清晰的纯图像和高信噪比的纯干涉条纹.对该系统的图像和光谱偏振复原过程进行了理论分析和数值摸拟,结果表明该系统可有效分离探测目标的背景图像和干涉图像,实现高精度的光谱复原和全偏振信息的有效提取,具有髙稳定性、高光谱、高灵敏度、高信噪比、信息复原精度高及数据处理复杂度低等优点,为偏振干涉成像光谱技术的发展提供了新思路.  相似文献   

4.
权乃承  张淳民  穆廷魁 《物理学报》2016,65(8):80703-080703
本文基于孔径分割、视场分割与通道光谱技术, 提出一种成像光谱偏振技术的新方案. 本方案在单一面阵探测器上同时获取经过不同强度调制的两对正反相干涉图, 四幅干涉图相加获取强度加倍的目标图像, 正反相干涉图相减获取纯干涉条纹, 纯干涉条纹相加减获取强度加倍的单通道干涉条纹, 对单通道干涉条纹进行傅里叶变换获取目标的光谱与偏振信息. 文中描述了方案的原理结构, 推导出了干涉强度的表达式, 并利用计算机仿真验证了方案的可行性. 为新型成像光谱偏振仪的设计和工程化应用提供了一种新思路.  相似文献   

5.
严新革  张淳民  赵葆常 《物理学报》2010,59(5):3123-3129
基于自行研制的时空混合调制型偏振干涉成像光谱仪(TSMPIIS),提出了一种新的干涉图和光谱的获取模式,分析了干涉数据的排列方式,详细阐述了不同时刻获得的一系列干涉图组合的方法,并由TSMPIIS获得了单色光和复色光的干涉图.理想的干涉图和复原光谱充分显示了这种探测模式的优越性,如宽场、高探测灵敏度和高通量等. 关键词: 时空混合调制 偏振干涉成像光谱仪 获取模式  相似文献   

6.
李晓翼  孔繁锵 《光子学报》2007,36(B06):290-294
基于空间干涉调制成像光谱仪的成像特点,提出了一种适合于千涉多光谱图像的不等重要性权值率失真斜率提升图像压缩算法.该算法根据退卷积技术对复原光谱信噪比的影响,推导出时域中随着光程差的增大,干涉图像压缩失真对频域中光谱曲线的信噪比影响越大.对各个码块的率失真斜率按空间域中各光程差对恢复光谱信息的贡献重要性不同赋予不同的重要性权值,增大对光谱信息的保护程度,使图像在相同的光谱分辨率下拥有更好的空间分辨率.实验结果表明,该算法比传统算法更好地保护了多光谱图像的光谱信息,在8倍压缩比下,满足该类干涉多光谱图像压缩系统的质量要求.  相似文献   

7.
研究了基于Savart偏光镜的偏振干涉成像光谱仪在时空混合调制模式下图像形成、数据分布的特点,论证了视场补偿型偏振干涉成像光谱仪更适用于单色光条件下的时空混合调制工作模式,并提出了时空混合调制模式下数据采集与处理的基本原理及其需要注意的问题与解决方法.最后,应用这种方法对实验获取的干涉图进行了数据处理,并成功复原出了光谱.  相似文献   

8.
时空联合调制型空间外差干涉成像光谱仪(TS-SHIS)在对目标推扫成像过程中,指向镜推扫误差、指向镜定位误差或卫星运动平台振动等会引起目标对应像点(x′,y′)偏离理想位置(x,y),导致其与相邻的若干空间分辨单元之间存在光谱掺杂现象,进而影响干涉数据重构及复原光谱精度。基于TS-SHIS机理,针对运动误差引起的目标光谱线性混叠、不同程度的地表反射率差异对复原光谱精度的影响等问题进行了分析;建立了以相邻目标掺杂比、地表反射率差异为变量的混合目标干涉函数关系。依据MODIS卫星载荷观测数据,对中国地区不同空间分辨率地表反射率差异进行了分析;以相对光谱二次误差为评价函数,讨论了典型高轨平台姿态参数对不同空间分辨率目标复原光谱精度的影响,该研究为下一代高轨、高时空分辨温室气体探测技术提供技术基础。  相似文献   

9.
静态傅里叶变换超光谱全偏振成像技术   总被引:4,自引:0,他引:4       下载免费PDF全文
李杰  朱京平  齐春  郑传林  高博  张云尧  侯洵 《物理学报》2013,62(4):44206-044206
光谱偏振成像技术是成像光谱技术与偏振成像技术的有机融合, 是当前空间光学遥感技术研究的热点和前沿. 针对目前光谱偏振成像技术受测量原理、探测模式的限制, 普遍需要运动、电控调制等部件, 导致体积大, 结构复杂, 加工装调困难, 抗振能力差等问题, 我们于2010年在国际上首先提出了一种多信息融合的静态傅里叶变换超光谱全偏振成像方法. 本文在此基础上, 阐述了新方法的基本原理, 给出了具体实现方案. 新方案无需运动、电控调制部件, 可实现目标图像、光谱、全偏振信息的一体获取. 推导出了新方案的调制干涉强度数据表达式及Stokes矢量解调公式, 分析了新方法实现光谱、全偏振探测的物理过程. 对新方案进行了计算机数值模拟验证, 研制了原理验证样机开展了室内、室外验证实验, 首次获得了室外推扫光谱图像数据立方体和全色全偏振度图像, 模拟及实验结果均表明新方案原理正确, 技术可行. 上述研究为新型空间遥感器的开发提供了基础理论及实践支持. 关键词: 成像光谱 偏振成像 Stokes矢量  相似文献   

10.
干涉型光谱成像技术是一种新型的光谱成像技术,近些年来发展迅速。在星载使用时,由于卫星数据传输容量的限制,需要对干涉成像光谱仪获得的原始干涉数据进行压缩,然后经过数据传输,到地面进行解压缩,再进行光谱复原处理,才能交给用户使用,干涉数据的压缩是一项新的技术,国内外很少有专门的文献进行介绍,基于该单位对此技术多年的研究,针对空间调制型干涉光谱成像仪数据的特点,结合环境与灾害监测预报小卫星星座A星超光谱成像仪的数据,提出了一种针对空间调制型干涉成像光谱仪的数据压缩方法,获得了很好的结果。  相似文献   

11.
Three different methods of spectrum reproduction and interferogram processing are discussed and contrasted in this paper. Especially, the nonparametric model of MUSIC (multiple signal classification) algorithm is firstly brought into the practical spectrum reconstruction processing. The experimental results prove that this method has immensely improved the resolution of reproduced spectrum, and provided a better math model for super advanced resolving power in spectrum reconstruction. The usefulness and simplicity of the technique will lead the interference imaging spectrometers to almost every field into which the spectroscopy has ventured and into some where it has not gone before.  相似文献   

12.
The objective surface is considered as the scattering plane; frequency spectrum of a digital hologram transmission light is studied when the reference light and reconstruction wave are spherical waves. The relation between relevant parameters and the object light, conjugate object light and zero-order diffraction wave frequency spectrum distribution. The research results show that: each frequency spectrum of the diffracted wave broadens to various degrees as the radius of the reconstruction wavefront decreases, and frequency aliasing is generated under certain conditions. Based on the research results, a new method that carries out high-pass filtering processing without zero-order diffraction interference upon digital hologram is proposed and the reconstruction experimental proof for eliminating the interferential changeable magnification wave is given.  相似文献   

13.
Theoretical grounds of the new method of monitoring of the temporal variability of oceanic inhomogeneities, which uses the data on frequency shifts of interference maxima of the sound field, were described. The method is free of limitations on both the resolution of signals coming in individual modes (rays) and the adiabatic approximation underlying the conventional methods of inhomogeneity reconstruction. The monitoring sensitivity was estimated, which allows us to estimate minimum detectable changes in the speed of sound by measurement data on frequency shifts of local maxima. Experimental data on shifts of the frequency spectrum of a broadband low-frequency signal on a stationary path in a shallow sea were presented. On their basis, the possibility of applying this method to diagnose tidal variations was shown. Within a numerical simulation, model reconstruction of the frequency spectrum of background internal waves was considered on the basis of the data on measurements of the spectrum of frequency shifts of the interference maximum. The results of the spectrum reconstruction with and without focusing of the conjugate wave field are presented. The problems of monitoring stability and efficiency with respect to the interference pattern formed by various groups of modes were discussed.  相似文献   

14.
Ren W  Zhang C  Mu T  Dai H 《Optics letters》2012,37(13):2580-2582
The dispersion effect of birefringent material results in spectrally varying Nyquist frequency for the Fourier transform spectrometer based on birefringent prism. Correct spectral information cannot be retrieved from the observed interferogram if the dispersion effect is not appropriately compensated. Some methods, such as nonuniform fast Fourier transforms and compensation method, were proposed to reconstruct the spectrum. In this Letter, an alternative constrained spectrum reconstruction method is suggested for the stationary polarization interference imaging spectrometer (SPIIS) based on the Savart polariscope. In the theoretical model of the interferogram, the noise and the total measurement error are included, and the spectrum reconstruction is performed by using the constrained optimal linear inverse methods. From numerical simulation, it is found that the proposed method is much more effective and robust than the nonconstrained spectrum reconstruction method proposed by Jian, and provides a useful spectrum reconstruction approach for the SPIIS.  相似文献   

15.
A model reconstruction of the two-dimensional spatial spectrum is considered for an anisotropic field of background internal waves in shallow water. Solution of the inverse problem is based on the data on frequency shifts of the sound field interference maxima. Results of a numerical experiment are presented.  相似文献   

16.
Although the broadcast television (TV) spectrum is currently open for unlicensed operation in the USA, a considerably large geographic area still remains excluded from the unlicensed operation due to potential interference to the licensed users. However, it might be possible to reuse primary spectrum within the protection contour if the frequency reuse occurs inside a building that shields radio signals and reduces interference to the primary system. Interference to outdoor licensed users from the indoor operations can be minimized if the unlicensed users adjust their transmit power according to their locations in the building. This paper presents an analysis and effectiveness evaluation of a novel cognitive radio (CR) system which enables CRs to access the licensed spectrum inside a building in the area within the protection contour. The system utilizes an indoor sensor network for (i) interference sensing, (ii) CR transmit power control, to limit the interference to the outdoor primary receiving antennas. Power control model of the indoor system has been developed to estimate safe transmit power for the indoor users. Two cases have been considered; single-user single-sensor (single indoor user and single sensor), and multi-user multi-sensor. Based on the power control model, a power control algorithm has been developed and its effectiveness is assessed through simulations. The algorithm is effective in realistic propagation scenarios, e.g. when internal partition walls and multipath fading are present. The outage probabilities in these propagation scenarios are found and the procedure of determining the transmit powers for CRs is presented.  相似文献   

17.
针对光谱重构领域中光谱数据量较大与重构精度较低的问题,提出了一种光谱可调谐的光谱重构方法。在此之前国内外相关研究均是在数百条膜系的基础上进行,并且计算过程比较复杂,该方法利用10条膜系针对不同的单色光源进行实验并进行光谱重构。光谱重构数学模型可以用线性方程组AX=B表示,在实验过程中会受到多种误差源的干扰,如膜系加工与设计间的误差、探测器量子效率拟合误差、杂散光干扰误差以及灰度值选取的误差等。这些误差源造成了线性方程组变为病态方程,造成了目标光谱信息解算的不准确。在解算目标光谱信息的过程中,首先在400~900 nm波长范围内利用凸优化算法解出含有误差的目标光谱信息的初始值,并进行初次拟合,得出含有误差的光谱曲线。然后利用已知的光谱曲线信息判断目标光谱的有效波长范围,对目标光谱范围进行伸缩,在此范围内进行二次局部解算,得出局部波长内的光谱信息,然后对局部光谱信息进行局部拟合,结合初次拟合结果,得出新的目标光谱拟合曲线,进一步提高了光谱重构精度,以此类推,得出精度较高的目标光谱曲线。针对重构精度的评价指标不仅采用了国内外广泛使用的ARE,MSE与RQE,还首次提出了一种新的评价光谱重构精度的指标,即计算目标有效波长范围内每隔10 nm的MSE值,若每10 nm的MSE值小于0.1,则认为光谱重构精度达到了10 nm,该方法不仅有效避免了在求解出现严重偏离真实值的情况,还在凸优化解算过程中提供了约束条件,有利于提高重构精度。实验结果表明该方法在保证MSE,ARE与RQE高精度的条件下,每隔10 nm的MSE最小值达到了0.002 3。基于光谱可调谐光谱重构方法不仅达到了对目标光谱达到高精度重构的效果,而且实现了数据降维。此方法为光谱重构领域的工作方向提供了新的思路,在工程上具有较大的应用价值。  相似文献   

18.
A new method for detecting frequency shifts of acoustic field interference maxima is proposed. The method is based on the cross-correlation processing of frequency-swept signals. Perturbations of medium are modeled as variations in the frontal zone width. The potential of this method is analyzed in comparison with the known methods for measuring frequency shifts of interference maxima. A model reconstruction of the frontal zone variability is performed.  相似文献   

19.
Cognitive radio (CR) technology seems to be a promising candidate for solving the radio frequency (RF) spectrum occupancy problem. CRs strive to utilize the white holes in the RF spectrum in an opportunistic manner. Because interference is an inherent and a very critical design parameter for all sorts of wireless communication systems, many of the recently emerging wireless technologies prefer smaller size coverage with reduced transmit power in order to decrease interference. Prominent examples of short-range communication systems trying to achieve low interference power levels are CR relays in CR networks and femtocells in next generation wireless networks (NGWNs). It is clear that a comprehensive interference model including mobility is essential especially in elaborating the performance of such short-range communication scenarios. Therefore, in this study, a physical layer interference model in a mobile radio communication environment is investigated by taking into account all of the basic propagation mechanisms such as large- and small-scale fading under a generic single primary user (PU) and single secondary user (SU) scenario. Both one-dimensional (1D) and two-dimensional (2D) random walk models are incorporated into the physical layer signal model. The analysis and corresponding numerical results are given along with the relevant discussions.  相似文献   

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