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通过水下布放的垂直线列阵采集空中声源在水下激发的测量声场,采用声场波数积分模型(OASES模型)对空中声源激发的水下声场建模,计算出拷贝声场,将二者进行匹配处理从而对空中声源目标定位。首先通过数值仿真验证了匹配场处理技术对空中声源的测距能力,并通过引入宽带匹配场处理器平滑掉距离上的周期性旁瓣。最后分析南海某海域的空气声试验数据,采用常规匹配场方法对700 m以内的32组空中声源目标进行定位,测距结果与GPS计算的收发间实际距离相比,大多数情况下是一致的,在较远距离由于信噪比降低,测量结果容易出现偏差。 相似文献
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G. Indebetouw 《Optics & Laser Technology》1986,18(5)
The reconstruction of coded aperture images using an optical scanning heterodyne processor is described for a class of apertures which can be synthesized by two beam interference. The analysis of Fresnel zone apertures indicates that a lateral and longitudinal (tomographic) resolution close to the theoretical limit is achievable. Experimental results of optical simulations confirm this assertion. Advantages of such technique include real-time operation and large multiplexing capability. 相似文献
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提出了一种基于全息光处理器的可调光编码-解码器的实现方案.这种新结构的可调光编码/解码器减小了硬件实现的复杂性,降低了成本和功耗,便于集成. 相似文献
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A novel method, designated the holographic spectrum reconstruction (HSR) method, is proposed for achieving simultaneous display of the spectrum and image of an object in a single plane. A study of the scaling behaviour of both the spectrum and the image has been carried out and based on this study, it is demonstrated that a lensless coherent optical processor can be realized. 相似文献
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为了实现烟羽二维空间分布的精确重建, 建立了被动多轴差分吸收光谱断层扫描系统,实现了多台被动多轴差分吸收光谱系统对废气烟羽空间分布的测量。首先,介绍了多轴差分吸收光谱系统及其反演气体浓度的机理。接着,使用代数迭代算法对不同的重建模型,采用不同的扫描光路进行了重建模拟,并设计了重建程序。然后,对数值模拟仿真结果进行了分析比较。最后,搭建了多轴差分吸收光扫描系统平台,进行了外场试验。数值模拟的结果显示:MAX-DOAS层析技术能精确的重建出烟羽模型的二维空间分布,四光源光路的重建误差约是双光源光路重建误差的三分之一,四光源重建时间约是双光源重建时间的四分之一,且双峰模型的重建误差大于单峰模型的重建误差。外场试验的结果显示:重建图像的积分数据与多轴差分吸收光谱测得的投影数据是一致的,说明重建出的烟羽空间分布符合实际情况。研究表明,数值模拟的结果与外场试验的结果具有一致性。 相似文献
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This study deals with the simulation of the image formation involved by using a nonlinear image processor composed of a nonlinear medium placed at the common focus of a 4-f system. A simple linear model is developed taking into account the third-order optical nonlinearity of the medium (in the general case of nonlinear absorption and dephasing) and the optical transfer function of the 4-f system. The simulated images through the system are given for phase and/or amplitude rectangular objects. Our model and its corresponding simulation lead to optimizing nonlinear parameters of the medium for this class of objects, whatever their transmittance is, in order to enhance the visibility in image processors. 相似文献
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A two-level classifier has been designed for use in a moment-based hybrid optical/digital processor. The simulation performance of this pattern recognition system using real IR input test images of ships and reference moments obtained from ship models is described with emphasis given to the preprocessing operations required. 相似文献
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In this paper, the probability of fade is performed for the airborne laser communication systems considering both the atmospheric and aero-optic effects. The atmospheric fluctuation is characterized by the exponentiated Weibull (EW) fading channel. The novel analytical expression is derived for probability of fade according to Meijer’s G function. The probability of fade is demonstrated to the simulation data with the Gamma–Gamma and log-normal distributions. The probability of fade is obtained for different flight altitudes and propagation distances. The probability of fade is analyzed in the airborne laser communication systems under the effect of aperture averaging in weak-to-strong turbulence regime. Results suggest that the proposed EW model is valid in airborne laser communication with high altitude, especially in the lower values of the irradiance under atmospheric turbulence and aero-optics effect. The fading of outage performance can be effectively mitigated by aperture averaging. Furthermore, this work is helpful for the compensate technique of system performance on airborne optical communication system. 相似文献
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自适应光学系统要求波前传感器能实现动态实时测量,曲率波前传感技术符合这一发展要求。一种新型的基于扭曲衍射光栅的曲率波前传感器在探测装置的实现方法方面具有较大优势,其波前重构已应用于光学度量。根据衍射光学理论,对其探测信号进行数值模拟,并利用Neumann边界条件的Green函数法对其波前重构进行数值模拟。结果表明:Green函数法归结为2矩阵相乘,计算速度快,达到实时重构要求; Green函数法对阶数不高的Zernike多项式重构效果较好;影响重构误差的主要因素是光强梯度的边界噪声。 相似文献
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A technique of pseudocolor encoding of spatial holographic imaging by a multslit rainbow process is illustrated. The encoding takes place at the spatial frequency plane of a coherent optical processor. The pseudocolor hologram imaging is obtained by white light reconstruction of the multiplexed rainbow hologram. The basic advantage of this technique as compared with the multiwavelength technique is the elimination of multicoherent sources. This multislit technique provides a simple encoding process for which a broad range of pseudo-color holographic images can be easily obtained. The potential applications of this technique may range from aerial photography for remote sensing to X-ray transparencies for medical diagnosis. 相似文献
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Lushnikov PM 《Optics letters》2002,27(11):939-941
An efficient numerical algorithm is presented for massively parallel simulations of dispersion-managed wavelength-division-multiplexed optical fiber systems. The algorithm is based on a weak nonlinearity approximation and independent parallel calculations of fast Fourier transforms on multiple central processor units (CPUs). The algorithm allows one to implement numerical simulations M/2 times faster than a direct numerical simulation by a split-step method, where M is a number of CPUs in a parallel network. 相似文献
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An all-optical adder/subtractor (A/S) unit with the (TOAD) is proposed. The all-optical A/S unit with help of terahertz optical asymmetric demultiplexer a set of all-optical full-adders and optical exclusive- ORs (XORs), can be used to perform a fast central processor unit using optical hardware components. We try to exploit the advantages of TOAD-based optical switch to design an integrated all-optical circuit which can perform binary addition and subtraction. With computer simulation results confirming the described methods, conclusions are given. 相似文献
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微型投影机光学引擎的研究 总被引:1,自引:0,他引:1
设计了一种针对个人用户使用的微型投影机光学引擎,系统为单片式数字光线处理器结构,采用红绿蓝三色大功率高亮度发光二极管作为光源,使用X棱镜作为合色元件,从而实现38.1~50.8 cm的彩色投影显示.对设计结果进行理论分析后可知,设计结果满足投影显示对颜色的要求,光学引擎的理论效率为16.1%.同时利用Light Tools仿真软件对系统进行建模分析,300万条光线追迹仿真的结果表明,光学引擎的效率为14.6%,与理论分析结果基本符合,屏幕上光通量为22.8 lm,其美国国家标准协会规定的九点照度均匀性达到91.55%和-93.36%,满足设计要求. 相似文献
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为满足机载光电系统的成像作用距离要求,对机载光学整流罩以及扫描反射镜的设计尺寸进行了理论仿真分析计算,并对研制的样机进行了试验研究。以实例形式给出了整流罩设计的作用距离与相关参量的计算结果,讨论了整流罩扫描系统的渐晕大小。装备该整流罩系统的样机,在近万米高空对音速某战机的红外长波扫描搜索距离可达到86 km,红外中波跟踪达到180 km,激光测距达到47 km。结果表明:根据探测作用距离理论模型分析计算,研制的机载光学整流罩及扫描反射镜光学系统达到了设计要求。 相似文献
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M. L. Jakobsen W. J. Hossack C. A. Greated W. J. Easson 《Optics and Lasers in Engineering》1993,19(4-5):253-260
An optical processor for generating a two-dimensional squared auto-correlation function is proposed in this paper. The incoherent-to-coherent conversion is performed by an optically-addressed spatial light modulator. The processor is meant to be used as integrated part of a system for post processing Particle Image Velocimetry (PIV) photographs of fluid flows. The optical processor to be able to present a fast and comparable alternative to the numerical processors, which typically are used for this purpose. This work demonstrates that the priciple is very promising. 相似文献
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机载激光测深中激光传输通道的光学特性 总被引:4,自引:1,他引:3
光在海洋中的传输特性对于机载激光测深有着重要的意义。本文从分析海水对光的吸收和散射的特性出发,对机载激光测深的海洋传输特性进行细致的讨论,并阐述其对机载激光测深的影响。 相似文献