低噪声小型化焦平面驱动与信息获取系统设计

在红外探测器的应用中,驱动电路及信息获取系统的质量将直接影响到红外成像系统的性能。针对320×256短波红外焦平面器件,提出了焦平面驱动及信息获取系统的低噪声小型化的设计方法,并利用TEC技术实现了焦平面的精密低温控制。该系统具有体积小、功耗低、精度高、灵活性好等特点,为红外探测系统的高性能和小型化设计提供了良好的基础。     

基于ACTEL FPGA短波红外成像系统设计与研究

针对短波红外探测在各个领域的重要作用,采用Sofradir320×256短波红外探测器,基于ACTEL公司的FPGA芯片APA600,设计并实现了短波红外成像系统,并对几个关键性设计进行了分析。该系统具有低功耗、小体积、高速率、可控性好等特点。实验结果表明该系统能够满足设计要求。     

基于Zigbee技术的热释电红外报警器设计

为了满足报警器智能化和网络化的发展需求,提出了一种基于zigbee技术的热释电红外报警器的设计方案,并完成了系统的软硬件设计。在硬件设计上,重点描述了热释电红外传感器和CC2530片上系统的电路设计;软件部分采用了zSTACk协议栈,描述了红外报警和zigbee组网的相关软件流程。实际应用表明,该系统具有功耗低、组网方便的特点,达到了设计要求。     

基于国产显控终端的实时红外图像仿真系统的研究

针对现有的红外仿真系统工程化程度低和国产化程度低的问题,设计并实现了一款实时红外图像仿真系统并成功应用在国产显控终端上。首先,分析红外仿真原理和构建红外仿真链路;其次,构建了一个基于OpenGL与GLSL着色器语言轻量级的红外仿真框架;然后,将所提出的红外仿真系统部署在基于国产CPU芯片FT2000+国产GPU芯片GB01显控终端上;最后,经实验验证所提出的实时红外仿真系统的有效性和实时性。     

基于DSP的现场级数字消防系统

分析了数字化消防系统的特点,针对消防现场的特殊需求,主要解决了红外图像的压缩算法和红外视频编码方案设计;设计了无线通信的主动和被动两种通信模式,以克服恶劣工作环境的限制;重点阐述了CPLD＋DSP方式的硬件系统,简要介绍了系统的软件结构.     

红外传感器在无人机姿态平衡系统中的应用

为简化小型无人机内环控制的复杂程度,提出了使用红外温度传感器设计小型无人机平衡系统,以此替代传统的MEMS等惯性元件实现无人机内环控制的思路.介绍了红外平衡系统的原理、组成和整体结构;通过论述TS105-3型红外温度传感器的功能参数和内部结构,以及处理器在数据采集和控制量输出等方面的设计,介绍了该系统的硬件组成和工作原理,以及小型无人机姿态平衡系统在软件功能规划等方面的具体设计,并给出了软件流程图.     

用于海陆空目标分析的SATIR多光谱红外系统

CEDIP红外系统公司向法国Cazeaux空军基地提供了一种新型SATIR多光谱红外分析系统。SATIR系统可用于搜集3个主要红外波段(1～2.5μm,3～5μm和8～12μm)的飞机、直升飞机和导弹的红外特征波形。其先进的摄像机设计使操作员能够收集并存储每一个红外波段的实时序列图像以便于后处理。每部摄像机均配置一个600mm透镜,因此能提供<1°的非常窄的视野。SATIR系统采用流行的JADE摄像机作为主要传感器,并为之配置了实时图像处理和存储工作台。CEDIP红外系统公司是一家专门设计并制造红外分析和温度测量的红外系统的公司。(www.cedip-in…     

基于DMD的动态红外景象仿真系统

基于DMD的动态红外景象仿真系统以全数字化、高图像质量等优越的性能,在红外成像系统半实物仿真性能测试中得到越来越多的关注.文中介绍了基于DMD的动态红外景象仿真系统的基本组成与工作原理;建立了系统的性能指标体系,包括帧频、视场、出瞳口径、空间分辨率、温度分辨率、温度范围、图像对比度等,并给出系统主要性能参数的选择与确定方法;分析了系统的关键技术,如窗口更换、数据处理电路和驱动电路设计、红外照明光源设计、红外准直光学系统设计、红外热像逼真度修正等;最后指出DMD在实际应用中存在的问题,为系统设计、应用以及性能评价提供参考.     

EAST托卡马克等离子体广角红外与可见光集成诊断系统设计

针对EAST托卡马克等离子体中波红外与可见光集成诊断系统进行了设计。系统采用独特的光路形式,使成像指标满足的同时,尽量避免光学元件受到辐射和污染;通过采用分色方式,实现中波红外与可见光两路同口径、同视场成像,提高了观测效率。最终设计完成了通光口径3 mm,视场5847的广角红外与可见等离子成像系统。装调后对各项指标测试结果表明,系统性能达到设计要求。通过对EAST托卡马克装置的放电过程成像实验表明,系统红外与可见两路实现了广角、清晰等离子成像。     

基于DMD的动态红外投影系统分光系统设计

动态红外投影技术是红外硬件闭环仿真(HWIL)和红外成像测试与评估的关键技术,它能够在实验室内实物模拟红外成像,从而降低光电系统的研发成本和提供可重复的实验环境。介绍了动态红外场景投影技术及其分类,描述了基于DMD动态红外场景分光系统的设计过程。为了解决系统中分光的问题,采用棱镜设计的理论设计了分光棱镜,给出了设计结果,经验证满足要求。为了获得更好的透过率和更紧密的结构,可以选取更好的材料来改进设计。     

Multirate digital filters, filter banks, polyphase networks, andapplications: a tutorial

The basic concepts and building blocks in multirate digital signal processing (DSP), including the digital polyphase representation, are reviewed. Recent progress, as reported by several authors in this area, is discussed. Several applications are described, including subband coding of waveforms, voice privacy systems, integral and fractional sampling rate conversion (such as in digital audio), digital crossover networks, and multirate coding of narrowband filter coefficients. The M-band quadrature mirror filter (QMF) bank is discussed in considerable detail, including an analysis of various errors and imperfections. Recent techniques for perfect signal reconstruction in such systems are reviewed. The connection between QMF banks and other related topics, such as block digital filtering and periodically time-varying systems, is examined in a pseudo-circulant-matrix framework. Unconventional applications of the polyphase concept are discussed     

Le problème des erreurs en transmission numérique de télécopie

The problem of errors in digital facsimile transmission is first introduced with references to various error protection methods. A new method is then presented for objective measurement of coding algorithms error susceptibility. The results obtained using this method are given, first for the case of one-dimensional coding algorithms and then for two-dimensional ones. Conclusions are drawn concerning the degree of acceptability of coding systems in facsimile equipments for the general switched telephone network. In conclusion, the very general nature of the proposed methodology is mentioned, which might be used for evaluating error susceptibility of most digital message transmission systems (pictures, written materials, sounds...).     

Distributed Joint Source-Channel Coding of Video Using Raptor Codes

Extending recent works on distributed source coding, this paper considers distributed source-channel coding and targets at the important application of scalable video transmission over wireless networks. The idea is to use a single channel code for both video compression (via Slepian-Wolf coding) and packet loss protection. First, we provide a theoretical code design framework for distributed joint source-channel coding over erasure channels and then apply it to the targeted video application. The resulting video coder is based on a cross-layer design where video compression and protection are performed jointly. We choose Raptor codes - the best approximation to a digital fountain - and address in detail both encoder and decoder designs. Using the received packets together with a correlated video available at the decoder as side information, we devise a new iterative soft-decision decoder for joint Raptor decoding. Simulation results show that, compared to one separate design using Slepian-Wolf compression plus erasure protection and another based on FGS coding plus erasure protection, the proposed joint design provides better video quality at the same number of transmitted packets. Our work represents the first in capitalizing the latest in distributed source coding and near-capacity channel coding for robust video transmission over erasure channels.     

Data compression systems for home-use digital video recording

The authors focus on image data compression techniques for digital recording. Image coding for storage equipment covers a large variety of systems because the applications differ considerably in nature. Video coding systems suitable for digital TV and HDTV recording and digital electronic still picture storage are considered. In addition, attention is paid to picture coding for interactive systems, such as the compact-disc interactive system. The relation between the recording system boundary conditions and the applied coding techniques is outlined. The main emphasis is on picture coding techniques for digital consumer recording     

Protection contre les erreurs en enregistrement magnétique numérique de télévision

In this paper the authors present the main problem of operating video tape recorders for television production, viz. picture degradations through multiple generations, which could be cancelled by using digital machines. Efficient error protection is mandatory. Burst error statistics are given as collected on a laboratory digital recorder as well as a physical interpretation. Different protection methods are used for luminance and colour differences, which results in sharing the available redundancy between two distinct coding systems. Adequate codes are selected through the use of two bounds stated as theorems. The main parameters of a possible system are presented. They are likely to be improved when further information is available to make an operating system practical.     

Analog diversity coding to provide transparent self-healingcommunication networks

pg 100 diversity coding, as introduced in Ayanoglu et al. (1990), is a method of protection against failures in a communication network or a storage system, which is based on introducing a digital error-correcting code across independent links. This technique makes efficient use of the extra network capacity needed for coding and has the additional advantages of being nearly instantaneous, not requiring a feedback channel, rerouting, or resynchronization. In high-speed (multi Gbps) networks, digital coding will be difficult to implement, and the purpose of the present paper is to demonstrate how diversity coding may be implemented in the analog domain using the discrete fourier transform (DFT). In particular, the authors show that the DFT is a continuous-amplitude maximum-distance separable code over the field of complex numbers when the transform kernel is a prime root of unity. This code can be used to generate self-healing or fault-tolerant communication networks for continuous- or discrete-amplitude signals, as long as continuous-amplitude parity channels are available. The authors describe electrical and optoelectronic implementations, and a signal estimation approach to combat channel noise and thereby improve the performance of the analog diversity coding system. The most important advantage of this technique is in greatly simplifying the encoders and decoders of diversity coding systems for high-speed networks, such as fiber-optic wavelength division multiplexed networks. Application of analog diversity coding to systems with analog sources, such as telemetry systems is also possible     

全数字电视制作系统的设计考虑

在全数字电视制作系统的设计中，选择数字编码方式和接口形成是关键。本文通过对分量数字与复合数字，串行数字传输与并行数字传输的分析比较，以及考虑到先建立的数字制作系统必须能与后建立的全台数字化大系统联网运行，最后选定了分量数字和串行数字接口方式。     

运用删截卷积码实现不等错误保护

在数字通信系统中，发送的数据序列中的比特往往具有不等的重要性。为了寻求更可靠的信息传输，人们提出了一些不等错误保护（UEP）编码方案。本文介绍了一种通过删截卷积码（CC）实现UEP编码的方案，并通过仿真分析了该UEP编码的性能。仿真结果表明，运用删截卷积码实现的UEP编码能获得较好的性能。