中长波红外偏振成像对比试验研究

基于高灵敏度的中波和长波制冷焦平面探测器, 搭建了红外偏振成像系统, 针对特定场景中的典型目标, 开展了红外偏振试验,获得了有效的试验数据, 并对图像进行了定性分析和定量评价。对比研究表明: 长波红外偏振成像易受水汽干扰, 但图像的平均灰度和平均梯度指标高; 中波红外偏振成像抗云干扰和观测人工防伪网能力强, 图像标准方差比较高。根据中长波红外偏振成像的特性, 在实际应用中可以按需要进行波段选择。     

高分辨率长波红外连续变焦光学系统设计

针对高分辨率640×512元非制冷探测器,设计了一款6×长波红外连续变焦光学系统。该系统由6片透镜构成,工作波长为8~12μm,F数为1~1.1。根据变焦光学系统设计理论,确定了系统的机械补偿式变焦结构并构建了初始结构;对该系统的光学结构参数及凸轮变焦曲线进行了设计和优化。像质评价结果表明该系统在20~120mm焦距范围上实现了连续平滑变焦;在30 lp/mm空间频率处,全焦距范围调制传递函数值大于0.45,接近衍射极限;全焦距范围各视场弥散斑均方根半径小于6.3μm,远小于像元尺寸17μm。实验证明该系统具有高分辨率、高变倍比、大光圈、大视场范围的特点,且像面稳定,变焦平滑,结构紧凑合理,成本相对较低。     

New solitary wave solutions for generalized regularized long-wave equation

In this paper, the sine–cosine and the tan h methods have been used to obtain solutions of the generalized regularized long-wave equation. New solitary and periodic solutions are formally derived. The change of parameters, that will drastically change the characteristics of the equation, is examined.     

创新与经济长波之间的关系研究

经济波动是供给和需求这一对矛盾运动的必然结果。经济波动是以长波为基础的短经济周期叠加上去的波动形态。自市场经济产生以来,推动经济长波的力量除了在自然经济阶段已具有的3种力量外,又增加了市场竞争力,它促进了经济长波的进一步缩短。竞争力推动了创新,创新成果的形成和扩散,推动了经济结构的调整和经济结构的转换。创新的过程实际是质量发展的过程。技术创新应分为6种形态。技术创新的实质就是通过质量创新来增加使用价值和实现交换价值。     

寒区路基遮阳的热流平衡模型及其应用

在路肩上铺设遮阳板是冷却多年冻土路基的一种重要工程措施,遮阳板上下表面及路肩的热流量控制其降温效果,但现有的研究大多分析实地遮阳板的降温效果以及遮阳板的设计参数。基于能量平衡原理,构建遮阳板与路肩的热流平衡理论模型并利用实测数据验证模型的准确性。经过对模型参数敏感性分析发现:减小遮阳板下表面热辐射系数可以有效地降低遮阳板到路肩表面的长波辐射量,从而降低路面温度。而增大遮阳板下表面的风速对减少路肩热吸收量的贡献很小。因此,减小板下表面的热辐射系数同时将遮阳板尽可能安设在接近路基表面的位置,此举既可以有效冷却路基又可以尽量避免遮阳板遭受风力破坏,有利于一步推广遮阳板的使用。     

长波红外广角地平仪镜头的光学设计

介绍适用于非致冷凝视式焦平面阵列的长波红外(LWIR)广角地平仪镜头的光学设计.其工作波长范围10～16μm,全视场角为135°.采用"负-正-正"型式的反远距像方远心光路镜头结构,仅有三块非球面锗透镜构成.能够很好地解决广角镜头轴外像差校正和像面照度均匀性问题.此镜头结构简单、体积很小、后工作距离大,成像质量接近于衍射极限,在20lp/mm空间频率处的调制传递函数值超过0.6,像高与视场角关系偏离线性的相对误差不超过15%.文中还分析了此镜头的加工和装调公差.     

Characterization of HgCdTe Diodes on Si Substrates Using Temperature-Dependent Current-Voltage Measurements and Deep Level Transient Spectroscopy

Reverse current in diodes can be dominated by generation processes, depending exponentially on temperature according to the rate-limiting step in the generation process. In this report, the current-voltage-temperature (IVT) relationship is analyzed for several midwave infrared and long-wave infrared (MWIR x = 0.295, LWIR x = 0.233) Hg_1−x Cd _x Te (MCT) diodes. The energy varied from diode to diode. At high reverse biases, the energy tends toward the band gap energy. Close to zero bias, the energy ranged from 0.06 to 0.1 eV. Deep level transient spectroscopy (DLTS) showed a broad peak centered at 55–80 K for the MWIR MCT. Comparison of the DLTS spectrum to a simulation based on the energy and capture cross section from a rate window analysis shows that the peak is a band of traps. The capacitance transient amplitude increased as the filling pulse increased from 1 μs to 0.1 s, consistent with capture at a dislocation. A shift to lower temperatures for the peak was also observed when the diodes are cooled under forward bias. The shift is reversible, indicating that the traps consist at least partially of a bistable defect.     

空间冷光学长波红外相机的设计与验证

为满足红外成像产品在复杂多变环境下的适应性并实现产品的使用功能,对空间冷光学长波红外相机设计进行了研究。首先进行了相机的结构设计;然后运用Partarn/Nastran有限元软件对相机进行了分析,探究了温降和重力对各透镜面形的影响,计算了相机的前三阶模态,并对相机进行了波像差测试;最后在真空低温环境下完成了相机的调制传递函数(Modulation Transfer Function, MTF)测试。试验结果表明,相机中心视场面形的均方根(Root Mean Square, RMS)值优于1/50λ,MTF计算值为0.18719,满足低温红外相机成像的精度要求。     

Performance Comparison of Long-Wave Infrared Imaging Spectrometer Between Dyson Form and Offner Form

In view of the difficulties in traditional long-wave infrared imaging spectrometer which is hard to realize a high signal-to-noise ratio and miniaturization as well under the weak remote sensing signal,Offner convex grating spectrometer and Dyson concave grating spectrometer,both having concentric structure,are designed and analyzed in the band of 8-12 μm. The diffraction angle expressions of the two spectrometers are obtained and the diffraction characteristics are acquired. Both of the spectrometers are designed in Zemax environment under different F-numbers and different grating constants with the same slit,spatial resolution,spectral resolution and detector. The results show that Dyson grating spectrometer possesses the advantages of higher throughput and smaller volume, and Offner grating spectrometer possesses the advantage of more accessible material and the absence of chromatic aberration. The differences between Dyson form and Offner form show that the former is a better choice in the long-wave infrared imaging spectrometer.     

轨道空间线形的运动检测算法

基于惯性测量平台,对惯性测量单元(IMU)信息进行等空间采样.采用经验模态分解算法(EMD)消除信号中的干扰成分,设计数字积分器对惯性信息进行积分计算,获取相对空间运动轨迹.实验结果表明:上述方法所测量的轨道三轴绝对位移精确度大于97.17%.