凝视焦平面探测器的空间采样效应建模仿真

为了增加红外凝视焦平面阵列探测器成像仿真的置信度,对探测器所存在的空间采样效应产生机理进行了分析,并且从空间域角度对其进行了建模,借助于基于图像像素处理的方法进行实验仿真;为了客观地评价空间采样效应对探测器成像质量的影响,定义了图像的负指数型平滑度,实验结果表明,叠加空间采样效应后探测器输出图像的平滑度减小了11.7%,图像局部波动变大,从而验证了红外探测器成像仿真中空间采样效应考虑的必要性。     

双色热图像信号的电子学处理及图像融合

利用ＢＳＴ非致冷焦平面探测器在２～１４μｍ的光谱响应的特性,可实现双色热成像系统。介绍双色热图的电子学处理及图像融合的部分电路构成及工作原理,电路由信号采焦（０视频信号Ａ／Ｄ化）、图像帧存储、主处理计算机及由可编程逻辑器件的控制与处理电路构成。     

基于FPGA的红外焦平面成像条纹噪声逐帧抑制算法的研究

红外焦平面阵列是当今红外成像技术发展的主要方向,随着器件工艺的进步,红外焦平面阵列探测器有了长足的发展,然而红外图像普遍具有信噪比低的缺点,这大大限制了红外焦平面的应用。与固定图案噪声（FPN）相比,随机噪声的最大特点是每帧均不同,因此去除该类型噪声的算法必须在一帧之内完成。提出了一种新型的单帧去除此类条纹噪声的算法并加以硬件实现,在单帧内设置适合的校正参数和阈值,达到在单帧图像内有效去除条纹噪声的目的。通过算法处理前后的图像对比以及客观的MSE、PSNR测试数据对比,证明了该算法能够有效地改善焦平面器件成像质量。     

热成像模式及其图像处理技术的研究与应用

热成像技术具有广泛的应用领域,随着红外焦平面探测器及数字图像处理技术的发展,新型热成像模式及其图像处理技术成为国内外发展的重要方向。介绍了近年来研究的几个典型进展,其中改进的基于场景特征的时域高通与空域低通滤波结合的非均匀性校正方法能够有效滤除制冷热成像系统观察低温天空场景时的水波纹固定图案噪声,并在FPGA硬件平台上实现了算法移植;研制出红外分焦平面偏振片阵列,实现了中波制冷和长波非制冷红外焦平面探测器的耦合成像,并通过考虑偏振片效应的偏振成像模型,滤除光路中偏振片的辐射影响;研制出基于常规制冷长波红外焦平面探测器的超频高动态热成像系统,在FPGA实现了多积分时间图像融合-细节增强级联的HDR图像融合方法,实现了对高动态场景的实时成像;研究了“田”字型四孔径和“十”字型四/五孔径等三类紧凑型视场部分重叠仿生复眼热成像模式,研制了2套实验系统来验证该方法的有效性;提出一种基于双生成对抗网络的非配对热红外-可见光图像转换算法TIV-Net,该方法能够将热图像有效地转化为类彩色可见光图像,并在无人机等平台实现了不低于20 Hz的实时处理。以上具有创新性的技术突破或已获得应用或展现良好的应用...     

环境温度对红外图像非均匀性影响的研究

定量分析了SOFRADIR公司生产的320×240凝视型非制冷焦平面探测器关键偏置电压FID、VEBASAGE对焦平面探测器输出的影响.通过测试发现,焦平面驱动电路板所处系统内部环境温度在某一温度附近有振荡现象,理论上推导出了焦平面驱动电路所处系统内部环境温度在（－10℃,40℃）的缓慢漂移以及振荡均能使关键偏置电压产生毫伏级漂移的结论.结果表明,焦平面驱动电路所处系统内部环境温度变化严重影响了焦平面探测器输出的稳定性并改变了红外图像的非均匀性,为基于环境温度补偿的非均匀性校正算法研究提供了依据.     

基于双TMS320DM642处理器的实时红外多目标图像处理系统

按照模块化设计理念,提出以TMS320DM642芯片为核心器件的实时红外多目标图像处理系统的设计方案,结合现场可编程门阵列FPGA完成对红外焦平面探测器输出图像数据流的实时采集、处理和输出。采用两级级联方式对多目标图像并行处理,提高图像处理的实时性。实验表明该系统处理一帧320×240分辨率的图像平均需要耗时15 ms,保证了对多目标跟踪的实时性。     

红外瞬态传感器

已完成的实验表明,非本征硅注入型红外探测器可用于模拟生物视觉系统中的瞬态神经响应。神经响应为视觉系统焦平面平行处理提供了一种高通滤波的方法。高通滤波强调图象的瞬时性。适用的红外成象应用包括:观测、运动传感及跟踪。红外探测器的输出脉冲足够大,因此不需要放大。这可以简化焦平面上或焦平面附近的平行处理。利用探测器及铺助电路的模型,对红外瞬态传感器方法进行定量分析。人们发现,模型和实验数据之间符合得很好。     

一种具有自适应非均匀校正功能的非制冷焦平面探测器组件

基于场景的非均匀校正算法(scene based nonuniformity correction,SBNUC)是非均匀校正技术今后的重点发展方向,介绍了近年来基于恒定统计约束的SBNUC、神经网络的SBNUC和运动估计的SBNUC算法的研究进展。研究了SBNUC算法在实际焦平面探测器组件上的实现方法,该方法仅依赖拍摄序列的信息对焦平面探测器的增益和偏置参数进行组间更新或帧间更新,可有效补偿温漂。研制了一种具有自适应非均匀校正功能的非制冷焦平面探测器组件,红外视频经该组件处理后,图像质量有所提高。该组件可明显提高热成像系统的成像性能,并能动态地保证热成像系统随场景变化的稳定性。     

高帧频384×288长波数字红外焦平面探测器

高帧频红外焦平面探测器在红外武器系统、光谱成像和高速测温中有着重要应用.目前,我国高帧频红外焦平面技术还比较落后,这严重制约着我国高端红外武器装备、光谱成像技术、高速测温仪器的发展.针对高帧频红外成像应用,设计并流片加工了一款384×288面阵、像元间距为25 μm的数字读出电路,与长波HgCdTe红外探测器芯片进行倒装互连,形成混合探测器芯片,并封装于金属真空杜瓦中,再配置斯特林制冷机,成功研制出了高帧频384×288长波数字红外探测器组件.经测试,所研制器件最高帧频达到1012 Hz,噪声等效温差(NETD)为16.8 mK,动态范围达到95.2 dB.采用所研制器件成功捕捉到了打火机点火瞬间的红外图像,该图像清晰呈现了火焰产生、迸出的过程,获得了良好的成像效果.     

百万帧频中波红外图像传感器研究

设计了一款64×64面阵规格、片上集成存储器的超高速红外焦平面数字读出集成电路,将其与中波红外焦平面探测器芯片进行了互连,成功研制出超高速64×64中波红外图像传感器.实验结果表明,所研制超高速红外图像传感器的帧频达到1 MHz,存储深度为100帧,对黑体温度呈现近似线性响应,具有优于3.6K的温度分辨率.     

基于二通道不可分加性小波的多光谱图像融合

提出了伸缩矩阵为[1,1;1,-1]的不可分小波的一种构造方法,并把它应用于多光谱图像与高分辨力全色图像的融合中。提出了一种二通道对称的不可分小波滤波器组的构造方法,设计出多组具有紧支撑、对称性和正交性的不可分小波6×6滤波器组,利用此类滤波器组中的低通滤波器对图像进行加性分解与重构。采用三种模式NAWS、NAWRGB和NAWL对ETM 及其它类多光谱图像与高分辨力全色图像进行融合研究。实验结果表明,该方法对多光谱图像与高分辨力全色图像的融合有较好的融合效果,与传统的融合方法相比,该方法既能保持多光谱图像的光谱信息,又能保持高分辨力全色图像的高分辨力特性,克服了传统张量积小波融合方法不能得到高分辨力图像的不足,并能节约运算量。     

Hyperspectral opportunities with next-generation QSIP arrays

Hyperspectral applications that employ gratings typically exploit only one grating order, since other orders that emerge from the grating at the same angle of dispersion would corrupt the spectrum measured with conventional FPAs. Previously, dualband infrared focal plane arrays (FPA), developed for multi-spectral imaging applications, have demonstrated advantages over conventional multi-FPA sensor configurations in compactness and band-to-band pixel registration. In addition, dualband and multiband FPA architectures of Quantum Structure Infrared Photodetector (QSIP) technology would enable applications beyond simple multi-spectral imaging. For example, In the case of dual- (or multi-) waveband FPAs, the different grating orders can be paired with the FPA wavebands, allowing high efficiency hyperspectral imaging over very broad wavelength regions. Exploiting the “third dimension” of FPA detecting layers for this type of hyperspectral application has been demonstrated previously. As time progresses, multi-waveband FPAs are expected to provide an increase in spectral information at the pixel level without the need for external (e.g. dispersive) optical elements. As the number of wavebands increases to the point of providing spectral overlap of adjacent spectral resolution elements, hyperspectral capability is then achieved by the FPA acting alone. This technology may someday become possible through advanced QSIP architectures having photons of different wavelength continuously absorbed at different depths, and their resulting photocurrents isolated with a vertical grid of contacts or an equivalent mechanism for transporting depth-dependent signal photocurrent to a read-out circuit unit cell.     

A new multi-spectral feature level image fusion method for human interpretation

Various different methods to perform multi-spectral image fusion have been suggested, mostly on the pixel level. However, the jury is still out on the benefits of a fused image compared to its source images. We present here a new multi-spectral image fusion method, multi-spectral segmentation fusion (MSSF), which uses a feature level processing paradigm. To test our method, we compared human observer performance in a three-task experiment using MSSF against two established methods: averaging and principle components analysis (PCA), and against its two source bands, visible and infrared. The three tasks that we studied were: (1) simple target detection, (2) spatial orientation, and (3) camouflaged target detection. MSSF proved superior to the other fusion methods in all three tests; MSSF also outperformed the source images in the spatial orientation and camouflaged target detection tasks. Based on these findings, current speculation about the circumstances in which multi-spectral image fusion in general and specific fusion methods in particular would be superior to using the original image sources can be further addressed.     

Detector and readout performance goals for quantum well and strained layer superlattice focal plane arrays imaging under tactical and strategic backgrounds

Advancements in III–V semiconductor based, Quantum-well infrared photodetector (QWIP) and Type-II Strained-Layer Superlattice detector (T2SLS) technologies have yielded highly uniform, large-format long-wavelength infrared (LWIR) QWIP FPAs and high quantum efficiency (QE), small format, LWIR T2SLS FPAs. In this article, we have analyzed the QWIP and T2SLS detector level performance requirements and readout integrated circuit (ROIC) noise levels for several staring array long-wavelength infrared (LWIR) imaging applications at various background levels. As a result of lower absorption QE and less than unity photoconductive gain, QWIP FPAs are appropriate for high background tactical applications. However, if the application restricts the integration time, QWIP FPA performance may be limited by the read noise of the ROIC. Rapid progress in T2SLS detector material has already demonstrated LWIR detectors with sufficient performance for tactical applications and potential for strategic applications. However, significant research is needed to suppress surface leakage currents in order to reproduce performances at pixel levels of T2SLS FPAs.     

θ调制多光谱照相中可见光与红外图像融合的研究

针对θ调制多光谱照相技术，提出了一种基于小波变换的图像融合及假彩色化新方法，其特点是使用改进的加权平均法融合可见光波段解码图像与红外图像的小波分解低频分量，以局部能量差为测度标准融合高频分量，将融合的图像在RGB空间合成假彩色图像.理论分析和实验结果表明该方法具有良好的融合性能和假彩色效果.     

基于荧光多光谱融合的水质化学需氧量的检测

为了对水中的有机污染物进行绿色、快速、准确的检测,提出了一种基于荧光多光谱融合的水质化学需氧量(Chemical Oxygen Demand, COD)的检测方法。实验样本为包含近岸海水和地表水在内的实际水样53份,采用标准化学方法获取样本的化学需氧量的理化值,利用荧光分光光度计采集样本的三维荧光光谱并对光谱数据进行处理和建模。在200～300 nm(间隔5 nm)的激发波长范围内将三维光谱展开成二维的发射光谱(发射波长范围250～500 nm,间隔2 nm)。采用ACO-iPLS(蚁群-区间偏最小二乘)算法提取发射光谱特征,PSO-LSSVM(粒子群优化的最小二乘支持向量机)算法建立预测模型,分别建立了单激发波长下的荧光发射光谱数据预测模型、多激发波长下发射光谱的数据级融合(LLDF)预测模型以及多激发波长下发射光谱的特征级融合(MLDF)预测模型,通过对预测效果的对比,得出结论。实验结果表明,对于不同激发波长下荧光发射光谱数据而言,265 nm激发光作用下的发射谱数据的预测模型最优,其检验集决定系数R2_P和外部检验均方根误差RMSEP分别为0.990 1和1.198 6 mg·L-1;对于荧光多光谱数据级融合模型(简写为：LLDF-PSO-LSSVM)而言,在235,265和290 nm激发光作用下的发射光谱的LLDF模型效果最优,其检验集的R2_ｐ和RMSEP分别为0.992 2和1.055 1 mg·L-1;对于荧光多光谱特征级融合模型(MLDF-PSO-LSSVM)而言,在265,290和305 nm激发光作用下的荧光发射光谱的MLDF模型效果最优,其R2_p=0.998 2,RMSEP=0.534 2 mg·L-1。综合比较各类建模结果可知,MLDF-PSO-LSSVM的模型效果最优,说明基于荧光发射光谱数据,采用多光谱特征级融合模型检测水质COD时,检测的精度更高,预测效果更好。     

多光谱与高分辨率图像融合算法研究

提出了一种多光谱与高分辨率图像融合的新算法.该方法将小波的多分辨分解与IHS变换相结合,它首先利用高分辨率图像各小波面叠加的边缘信息进行区域划分,再通过融合算子实现分区域融合,最后对融合后的强度分量进行IHS反变换,得到一幅同时具有较好空间分辨率和光谱信息的融合图像.实验结果表明,该方法得到的融合图像优于IHS变换法和小波变换法(WT法).     

Noise characteristics analysis of short wave infrared InGaAs focal plane arrays

The increasing application of InGaAs short wave infrared (SWIR) focal plane arrays (FPAs) in low light level imaging requires ultra-low noise FPAs. This paper presents the theoretical analysis of FPA noise, and point out that both dark current and detector capacitance strongly affect the FPA noise. The impact of dark current and detector capacitance on FPA noise is compared in different situations. In order to obtain low noise performance FPAs, the demand for reducing detector capacitance is higher especially when pixel pitch is smaller, integration time is shorter, and integration capacitance is larger. Several InGaAs FPAs were measured and analyzed, the experiments’ results could be well fitted to the calculated results. The study found that the major contributor of FPA noise is coupled noise with shorter integration time. The influence of detector capacitance on FPA noise is more significant than that of dark current. To investigate the effect of detector performance on FPA noise, two kinds of photodiodes with different concentration of the absorption layer were fabricated. The detectors’ performance and noise characteristics were measured and analyzed, the results are consistent with that of theoretical analysis.     

Material considerations for third generation infrared photon detectors

In the paper, issues associated with the development and exploitation of materials used in fabrication of third generation infrared photon detectors are discussed. In this class of detectors two main competitors, HgCdTe photodiodes and quantum well photoconductors are considered. The performance figures of merit of state-of-the-art HgCdTe and QWIP focal plane arrays (FPAs) are similar because the main limitations come from the readout circuits. The metallurgical issues of the epitaxial layers such as uniformity and number of defected elements are the serious problems in the case of long wavelength infrared (LWIR) and very LWIR (VLWIR) HgCdTe FPAs. It is predicted that superlattice based InAs/GaInSb system grown on GaSb substrate seems to be an alternative to HgCdTe with good spatial uniformity and an ability to span cutoff wavelength from 3 to 25 μm. In this context the material properties of type II superlattices are considered more in detail.     

微波后向散射数据改进农作物光谱分类精度研究

利用实验区环境星多光谱数据与Envisat ASAR VV极化数据进行融合.讨论了VV极化微波后向散射数据用于改善多光谱遥感数据农作物分类的精度,并比较了不同分类方法的分类精度.结果表明,两种数据之间的融合充分利用了环境星数据的光谱信息和VV极化数据对于地物结构敏感的特征,不但增强了不同地物之间的光谱差异,而且提高了作...