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1.
赵煜  吴平  孙文芳 《应用光学》2014,35(3):515-519
鉴于复杂大气条件下的红外系统作用距离难以精确、实时地计算,提出一种建立红外系统作用距离实时计算系统的方法。通过将MODTRAN软件与基于光谱等分法建立的红外系统作用距离模型有机地结合起来,实现对于MODTRAN软件自动写入配置及调用计算,简化了大气模型的配置方法,并能够自动读取MODTRAN生成的结果输出文件。对某探测目标在不同海拔高度(1 km~6 km)及不同降雨强度(0 mm/h~4 mm/h)下红外系统作用距离进行计算,结果表明:探测高度的变化对于红外系统作用距离有比较明显的影响,其中在1 km~3 km探测高度范围内,探测距离变化尤为明显。降雨对于红外系统作用距离影响巨大。降雨强度为1 mm/h时,红外系统作用距离衰减为无降雨时的50%。当降雨强度大于3 mm/h时,作用距离趋于稳定。  相似文献   

2.
一种基于离散光谱透过率的红外探测距离模型研究   总被引:1,自引:1,他引:1       下载免费PDF全文
马鹤  吴平  赵煜 《应用光学》2013,34(3):532-536
针对大气透过率是影响红外系统作用距离的重要因素,且随大气环境、波长、距离等因素而复杂变化难以精确描述,研究了大气透过率对红外系统作用距离的影响,提出一种基于离散光谱透过率的红外系统作用距离模型。使用MODTRAN 软件计算出波数间隔为1 cm-1的离散光谱大气透过率,建立大气透过率数据库,计算出波数间隔为1 cm-1的光谱区域内目标的红外辐射功率。应用该模型对实际的战斧巡航导弹进行计算,结果表明该模型具有更高的计算精确度与可行性。  相似文献   

3.
When performing line-by-line simulations of atmospheric high-resolution infrared spectra, a large portion of the computation time is spent in the calculation of the absorptions by the far wings of the absorption lines. For applications in which one is interested mainly in evaluating the effective absorption in a microwindow, a computationally less expensive method has been developed. The method is faster than the explicit line-by-line calculation by a factor proportional to the number of line wings that contribute to the absorption in the simulated microwindow. This paper presents the method and demonstrates its performances in the 700- infrared band. Typically one obtains a gain in computation time of order 25.  相似文献   

4.
王潜  李永贵 《光学技术》2002,28(6):547-548
针尖 样品的距离控制系统是扫描近场红外显微镜的重要组成部分。切变力探测作为一种重要的近场距离控制手段而得到了广泛的应用。介绍了一种对切变力探测系统的改进方法 ,它可以有效地提高石英晶振音叉的品质因数 ,进而提高探测系统对切变力感应的灵敏度。给出了理论分析和实验验证结果  相似文献   

5.
Based on the most advanced staring focal plane array which had a format of 640 × 480 and the pixel pitch of 15 μm, a set of all-sphere midwave infrared ahermalization optical system was designed. The working wavelength was in 3–5 μm, the full field of view was 8.58°, the relative aperture was 1/2, the efficient focal length (EFL) was 80 m. The opticalsystem consisted of four lenses with three kinds of material – Ge, ZnSe and Si. All surfaces were sphere, which was easier to process test, making the cost inexpensive, and it could avoid using diffractive surface and aspheric surface. The image quality of the system approaches the diffraction limit in the temperature range −60 °C-180 °C. The design results proved that, the high resolution midwave infrared optical system had compact structure, small volume, high resolution and excellent image quality, meeting the design requirements, so that it could be used for photoelectric detection and tracking system.  相似文献   

6.
紫外告警系统探测距离的估算   总被引:7,自引:0,他引:7  
介绍了紫外告警原理及紫外告警系统的结构组成。基于典型目标(导弹)的紫外辐射特征和紫外辐射的大气传输特性,结合紫外告警系统探测器件的性能参数,根据像平面照度公式,提出了紫外告警系统探测距离的估算方法及模型,实例计算并验证了紫外告警系统在不同观察方位角对固体推进剂导弹的探测距离。分析研究表明,改变CCD最小照度值,像管的增益,光学系统的透过率和相对孔径等探测传感器的性能参数,可以提高紫外告警系统的探测距离。  相似文献   

7.
To satisfy environment requirement of infrared search and trace optical system, an infrared diffractive/refractive hybrid optical system in 3.7–4.8 μm with 11.42° of field of view for passive athermalization is presented. The system is consisted of three lenses, including two aspheric surfaces and a diffraction surface, which has only two materials Ge and Si. The optical system has compact structure, small volume and light weight. The image quality of the system approaches the diffraction limit in the temperature range −80 °C to 160 °C. It is compatible with staring focal plane array which has a format of 320 × 240 and the pixel pitch of 30 μm. The system need not move the compensated lens repeatedly to obtain the best images from −80 °C to 160 °C and enhances the performance of target tracking and recognition.  相似文献   

8.
吴福田 《大学物理》2000,19(5):43-45
计算分析美国探测金星水手Ⅱ号宇宙飞船上安置的红外辐射计光学系统,说明了光学系统的光学特征、像差校正原理及其结构和应用特点.  相似文献   

9.
以R404A为工质,用热平衡法测试结霜工况下直接膨胀供液制冷系统以及重力供液制冷系统在不同蒸发器供液高度时的系统的运行特性,并进行比较。研究表明:在重力供液制冷系统中,蒸发温度和压力高于直接膨胀供液制冷系统,且受供液高度和环境温度影响;在不同供液高度时,重力供液制冷系统压缩机吸气压力高于直接膨胀供液制冷系统压缩机吸气压力,供液高度的增加,吸气压力升高,压缩机的排气压力的变化趋势与蒸发压力相似;重力供液制冷系统制冷量高于直接膨胀供液制冷系统制冷量,且随蒸发温度升高而增大,但制冷量的增加幅度却有着相反的变化趋势。供液高度为1200mm时,制冷量最大增幅达到35.59%;重力供液制冷系统COP大于直接膨胀供液制冷系统COP,重力供液制冷系统存在最佳供液高度。  相似文献   

10.
一种把三角法应用于中、短距离测量的方法   总被引:1,自引:0,他引:1  
三角法测距的原理公式中因变量、自变量及系统结构参数之间具有非线性关系,并且在系统结构确定之后,距离越远,单位距离变化在接收器件上的对应变化量越小,即测量分辨精度越低,测量精度与测量范围之间存在矛盾。通过采用一种新的距离分段的改进三角测距法,使远近距离都有一个比较适中的测量精度,较好地解决了测量精度与测量范围之间的矛盾。并给出其应用实例。  相似文献   

11.
许荣国  王雷  阴万宏  杨照金 《应用光学》2013,34(6):1000-1004
提出了一种变温条件下红外光学材料透过率测量评价方法。研究内容包括使用准直反射镜将红外光源变为平行光,通过斩波器变为脉冲光,再经滤光片选择波长;使用平面反射镜组与精密温控炉来获得变温条件下的双光路:测试光路与参考光路。使用前置放大电路和锁相放大器对红外微弱信号进行检测,根据两个光路的测量电压计算样品的透过率及透过率温度系数。计算机实现自动控制、采集与相关运算。该方法解决了变温条件下红外光学材料透过率测量中的实际应用问题,使光学材料参数检测从常规检测扩展到高温等极端条件,更接近于材料的实际使用条件,蓝宝石材料在波长5195 nm处,透过率高于10%,温度从室温到700℃的范围内,重复性优于0.2%。  相似文献   

12.
可见光液晶光谱成像系统研究   总被引:3,自引:0,他引:3  
利用向列相液晶材料的电控双折射效应,研制了用于可见光波段光谱调谐的大口径液晶可调滤光片,透过光谱测试表明,该滤光片在可见光波段(420~700 nm)以20 nm光谱分辨率可实现连续调谐和任意波长选择。利用该滤光片搭建了一种小型光谱成像系统,并在实验室内对若干样品进行了测试,结果表明,该系统可同时实现高图像分辨率和高光谱分辨率光谱成像,具备高、超光谱分辨率光谱成像的应用潜力,在生物医学、环境保护和资源探测等领域具有较好的应用前景。  相似文献   

13.
压力作用下石英砂岩的热红外光谱变化与敏感响应波段   总被引:1,自引:0,他引:1  
在实验室对石英砂岩进行单轴压缩加载,利用红外光谱辐射计(观测波段8~14μm)对加载过程中试样的红外光谱辐射变化特征进行观测,研究岩石红外辐射对应力响应的敏感波段。实验结果显示,当岩石被加载时,红外光谱随之发生变化,但不同波段变化特征不同,在8.0~11.5μm范围(尤其在8.6~9.1μm)石英砂岩的红外光谱辐射强度随载荷增加而增加,二者间近似呈两次曲线关系,且光谱辐射强度的"信噪比"较高;在其它波段光谱辐射强度与载荷的相关性差且"信噪比"较低。由此表明,8.0~11.5μm是石英砂岩红外辐射对应力响应的敏感波段,也是岩石应力与灾变红外遥感监测的优势波段,而最佳监测波段是8.6~9.1μm。  相似文献   

14.
In this paper, an interesting fusion method, named as NNSP, is developed for infrared and visible image fusion, where non-negative sparse representation is used to extract the features of source images. The characteristics of non-negative sparse representation coefficients are described according to their activity levels and sparseness levels. Multiple methods are developed to detect the salient features of the source images, which include the target and contour features in the infrared images and the texture features in the visible images. The regional consistency rule is proposed to obtain the fusion guide vector for determining the fused image automatically, where the features of the source images are seamlessly integrated into the fused image. Compared with the classical and state-of-the-art methods, our experimental results have indicated that our NNSP method has better fusion performance in both noiseless and noisy situations.  相似文献   

15.
吴翰钟  曹士英  张福民  邢书剑  曲兴华 《物理学报》2014,63(10):100601-100601
采用光学频率梳的高精度绝对距离测量技术在航空航天、科学研究和工业生产等领域都发挥着重要作用.提出一种利用光学频率梳技术,通过检测光强实现绝对距离测量的新方法,研究了光学频率梳发出脉冲的时间相干性,分析了光强与被测距离之间的关系、干涉条纹峰值点位置与被测距离之间的关系.建立了基于Michelson干涉原理的测距系统,通过测量光强信息得到被测距离.以高精度纳米位移平台的位移量作为长度基准进行了绝对测距实验,在每个被测距离点都重复进行了10次实验,将10次实验测得的光强值取平均后用于距离的计算.实验结果表明,该方法可以实现绝对距离测量,在10μm测量范围内,最大误差为47 nm.因此,该方法可以应用于大尺寸高精度的绝对距离测量.  相似文献   

16.
Infrared imaging simulation technology can provide infrared data sources for the development, improvement and evaluation of infrared imaging systems under different environment, status and weather conditions, which is reusable and more economic than physical experiments. A real-time infrared imaging simulation process is established to reproduce a complete physical imaging process. Our emphasis is put on the modeling of infrared sensors, involving physical effects of both spatial domain and frequency domain. An improved image convolution method is proposed based on GPU parallel processing to enhance the real-time simulation ability with ensuring its simulation accuracy at the same time. Finally the effectiveness of the above methods is validated by simulation analysis and result comparison.  相似文献   

17.
To improve the resolution of remote sensing infrared images, infrared scanning oversampling system is employed with information amount quadrupled, which contributes to the target detection. Generally the image data from double-line detector of infrared scanning oversampling system is shuffled to a whole oversampled image to be post-processed, whereas the aliasing between neighboring pixels leads to image degradation with a great impact on target detection. This paper formulates a point target detection method utilizing super-resolution (SR) strategy concerning infrared scanning oversampling system, with an accelerated SR strategy proposed to realize fast de-aliasing of the oversampled image and an adaptive MRF-based regularization designed to achieve the preserving and aggregation of target energy. Extensive experiments demonstrate the superior detection performance, robustness and efficiency of the proposed method compared with other state-of-the-art approaches.  相似文献   

18.
19.
Atmospheric radiation in the infrared (IR) 8–13 μm spectral region contains a wealth of information that is very useful for the retrieval of ice cloud properties from aircraft or space-borne measurements. To provide the scattering and absorption properties of nonspherical ice crystals that are fundamental to the IR retrieval implementation, we use the finite-difference time-domain (FDTD) method to solve for the extinction efficiency, single-scattering albedo, and the asymmetry parameter of the phase function for ice crystals smaller than 40 μm. For particles larger than this size, the improved geometric optics method (IGOM) can be employed to calculate the asymmetry parameter with an acceptable accuracy, provided that we properly account for the inhomogeneity of the refracted wave due to strong absorption inside the ice particle. A combination of the results computed from the two methods provides the asymmetry parameter for the entire practical range of particle sizes between 1 and 10,000 μm over the wavelengths ranging from 8 to 13 μm. For the extinction and absorption efficiency calculations, several methods including the IGOM, Mie solution for equivalent spheres (MSFES), and the anomalous diffraction theory (ADT) can lead to a substantial discontinuity in comparison with the FDTD solutions for particle sizes on the order of 40 μm. To overcome this difficulty, we have developed a novel approach called the stretched scattering potential method (SSPM). For the IR 8–13 μm spectral region, we show that SSPM is a more accurate approximation than ADT, MSFES, and IGOM. The SSPM solution can be further refined numerically. Through a combination of the FDTD and SSPM, the extinction and absorption efficiencies are computed for hexagonal ice crystals with sizes ranging from 1 to 10,000 μm at 12 wavelengths between 8 and 13 μm.

Calculations of the cirrus bulk scattering and absorption properties are performed for 30 size distributions obtained from various field campaigns for midlatitude and tropical cirrus cloud systems. Ice crystals are assumed to be hexagonal columns randomly oriented in space. The bulk scattering properties are parameterized through the use of second-order polynomial functions for the extinction efficiency and the single-scattering albedo and a power-law expression for the asymmetry parameter. We note that the volume-normalized extinction coefficient can be separated into two parts: one is inversely proportional to effective size and is independent of wavelength, and the other is the wavelength-dependent effective extinction efficiency. Unlike conventional parameterization efforts, the present parameterization scheme is more accurate because only the latter part of the volume-normalized extinction coefficient is approximated in terms of an analytical expression. After averaging over size distribution, the single-scattering albedo is shown to decrease with an increase in effective size for wavelengths shorter than 10.0 μm whereas the opposite behavior is observed for longer wavelengths. The variation of the asymmetry parameter as a function of effective size is substantial when the effective size is smaller than 50 μm. For effective sizes larger than 100 μm, the asymmetry parameter approaches its asymptotic value. The results derived in this study can be useful to remote sensing studies of ice clouds involving IR window bands.  相似文献   


20.
红外光谱响应度是红外探测领域的重要技术指标。介绍了红外光谱响应度的测试技术及其测试系统。该系统选用以无光谱选择的腔体热释电探测器为标准,用双单色仪进行分光同时,采用国际上最新的测试方法完成了红外波段光谱响应度的测量,获得了高的测量不确定度,分析了测试结果及其影响因素。  相似文献   

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