微型法-珀腔阵列光谱探测器读出电路的模拟与设计

针对微型法-珀腔阵列光谱探测器读出电路的单芯片集成化设计,在研究分析微型法-珀腔阵列光谱探测器的结构和工作原理的基础上,提出了基于2μm标准CMOS工艺的8位线阵微型法-珀腔阵列光谱探测器读出电路方案,研究了电路中各元器件的结构与结构参数,在ORCAD软件平台下完成了读出电路各单元电路与系统电路的设计、仿真与优化,利用TANNER软件完成了微型法-珀腔阵列光谱探测器读出电路的版图设计及版图验证。该电路工作电压为 5 V,总功耗为4.82μW,版图面积0.37 mm×0.22 mm。     

NaI(Tl)闪烁探测器测量γ射线的性能分析

本文提出NaI(Tl)闪烁探测器测量γ射线的性能要用灵敏度和垂直分辨率来表征.通过分析灵敏度的影响因素,探讨了灵敏度与灵敏体积的关系,提出了提高灵敏度的技术途径.在分析垂直分辨率影响因素的基础上,提出了提高垂直分辨率的技术途径,给出了确定垂直分辨率的经验公式,通过分析、比较,认为最小可分瓣厚度是垂直分辨率的逼近极限.这些结论,对于改进NaI(Tl)闪烁探测器设计,提高闪烁探测器的测量性能具有重要的指导作用.     

基于Fabry-Perot腔阵列光谱传感器的集成化研究

提出了一种微型集成化光谱传感器,其结构包括不同腔长的Fabry-Perot腔阵列、光电探测器阵列、读出电路几部分.一个光谱探测单元包括一个Fabry-Perot腔和其下的光电探测器,各Fabry-Perot腔腔长的不同,可实现对不同波长的检测.该光谱传感器无可动部件,结构性能稳定,用CMOS工艺和MEMS工艺实现一体化集成,制作体积为mm量级.文章中将详细阐述该传感器的各部分结构设计和工艺实现等问题.     

焦平面阵列读出电路研究和应用

焦平面(FPA)如果要获得较好的探测性能,就必须尽可能提高探测器的信噪比.读出电路因为可以很好地改善探测器的性能,获得快速的研究和发展,现已发展出多种结构形式,应用越来越广泛.本文主要介绍了各种读出电路的结构和应用.     

一种可实现高精度时间同步的数据传输方法

KM2A探测器阵列是高海拔宇宙线观测站(LHAASO)的主体探测器阵列之一,近7000个探测器平均分布在1.3 km 2的实验范围内。针对大面积分布式布局的高能物理实验中读出电子学系统的时间同步和数据传输问题,提出一种可实现高精度时间同步的数据传输方法。借助TCP/IP协议栈和White Rabbit时钟同步技术融合时钟网络与数据网络,TCP/IP协议栈在仅保留PC通信协议的基础上,无需增加额外硬件,即可实现高效可靠的数据传输和高精度时钟同步。测试结果表明,该方法可以实现探测器阵列内LHAASO KM2A读出电子学插件间时间同步精度优于1 ns,同时保证了数据传输的可靠性。     

多层次融合注意力网络的双目图像超分辨率重建

目的 随着深度卷积神经网络广泛应用于双目立体图像超分辨率重建任务,双目图像之间的信息融合成为近年来的研究热点。针对目前的双目图像超分辨重建算法对单幅图像的内部信息学习较少的问题,提出多层次融合注意力网络的双目图像超分辨率重建算法,在立体匹配的基础上学习图像内部的丰富信息。方法 首先,利用特征提取模块从不同尺度和深度来获取左图和右图的低频特征。然后,将低频特征作为混合注意力模块的输入,此注意力模块先利用二阶通道非局部注意力模块学习每个图像内部的通道和空间特征,再采用视差注意力模块对左右特征图进行立体匹配。接着采用多层融合模块获取不同深度特征之间的相关信息,进一步指导产生高质量图像重建效果。再利用亚像素卷积对特征图进行上采样,并和低分辨率左图的放大特征相加得到重建特征。最后使用1层卷积得到重建后的高分辨率图像。结果 本文算法采用Flickr1024数据集的800幅图像和60幅经过2倍下采样的Middlebury图像作为训练集,以峰值信噪比（peak signal-to-noise ratio,PSNR）和结构相似性（structural similarity,SSIM）作为指标。实验在3个...     

高分辨率可见光图像引导红外图像超分辨率的Transformer网络

目的 红外图像在工业中发挥着重要的作用。但是由于技术原因,红外图像的分辨率一般较低,限制了其普遍适用性。许多低分辨率红外传感器都和高分辨率可见光传感器搭配使用,一种可行的思路是利用可见光传感器捕获的高分辨率图像,辅助红外图像进行超分辨率重建。方法 本文提出了一种使用高分辨率可见光图像引导红外图像进行超分辨率的神经网络模型,包含两个模块：引导Transformer模块和超分辨率重建模块。考虑到红外和可见光图像对一般存在一定的视差,两者之间是不完全对齐的,本文使用基于引导Transformer的信息引导与融合方法,从高分辨率可见光图像中搜索相关纹理信息,并将这些相关纹理信息与低分辨率红外图像的信息融合得到合成特征。然后这个合成特征经过后面的超分辨率重建子网络,得到最终的超分辨率红外图像。在超分辨率重建模块,本文使用通道拆分策略来消除深度模型中的冗余特征,减少计算量,提高模型性能。结果 本文方法在FLIR-aligned数据集上与其他代表性图像超分辨率方法进行对比。实验结果表明,本文方法可以取得优于对比方法的超分辨率性能。客观结果上,本文方法比其他红外图像引导超分辨率方法在峰值信噪比(pea...     

光寻址电位传感器阵列信号处理仿真研究

基于微透镜和频率调制盘的设计,提出了光寻址电位传感器阵列(LAPS)中光脉冲阵列的频率调制方法和基本的测量系统.采用Matlab对LAPS阵列可能检测到的光电流信号进行快速傅立叶变换(FFT)和小波分析的仿真.从仿真得到的频谱图,各频率的脉冲光所对应的光电流能够分辨出来,进一步证明多频率脉冲光源LAPS传感器阵列具有很好的频域分辨率,从而得到LAPS阵列对应各个传感元的信号,为实际LAPS阵列器件的制作和信号处理提供了理论依据.     

一种强度调制型频率编码光纤环传感器阵列

提出一种基于强度调制技术的频率编码光纤环传感器。给出光纤传感阵列结构并阐述了多传感器准频分复用原理,分析了阵列中传感器的反射信号特征,并重点讨论了不同长度光纤环的谐振频率特性。结果表明,通过改变光纤耦合系数及选用合适的光纤环长度,可以提高传感系统的复用能力和分辨能力。系统采用频率跟踪解调技术以提高信噪比和探测灵敏度。此系统可用于准分布应变和温度的测量。     

基于低分辨率输入图像的年龄识别方法

针对通常获取到的人脸图像,由于分辨率较低会丢失人脸原本的皱纹等特征信息,从而降低年 龄识别的性能的问题,提出一种基于低分辨率输入图像的年龄识别方法：首先使用条件生成对抗网络(CGAN) 对输入的低分辨人脸图像进行重构,再采用深度学习方法进行年龄识别。并进行了关于图像重构的对比实验, 然后在不同的人脸图像数据集上进行了关于年龄识别的结果对比。通过与其他深度学习方法关于信噪比、峰值 信噪比与平均绝对误差的实验对比,表明了该方法在图像重构与年龄识别 2 方面的有效性。此外,对该方法的 时间复杂度进行了分析。     

The importance of Monte Carlo simulations in modeling detectors for Nuclear Medicine

Nowadays, Monte Carlo techniques are very common for the development of Nuclear Medicine systems. Simulations can be very helpful for the optimization of SPECT and PET cameras, and for investigating the importance of several physical effects involved in image formation. In this paper, a simulation study for evaluating various aspects inuencing image formation in detectors for Nuclear Medicine is presented. To this end, the EGSnrc Monte Carlo code has been used, which transports photons and electrons in any material and handling various physical phenomena. Here, some detector systems are simulated, consisting of a parallel-hole collimator and a pixellated scintillator. Various effects are investigated, such as electron transport, uorescence photons, collimator septa penetration. Results are evaluated by means of energy spectra, photon uxes, uniformity of response, SNR and spatial resolution.     

YOLOv3 Attention Face Detector with High Accuracy and Efficiency

In recent years, face detection has attracted much attention and achieved great progress due to its extensively practical applications in the field of face based computer vision. However, the tradeoff between accuracy and efficiency of the face detectors still needs to be further studied. In this paper, using Darknet-53 as backbone, we propose an improved YOLOv3-attention model by introducing attention mechanism and data augmentation to obtain the robust face detector with high accuracy and efficiency. The attention mechanism is introduced to enhance much higher discrimination of the deep features, and the trick of data augmentation is used in the training procedure to achieve higher detection accuracy without significantly affecting the inference speed. The model has been trained and evaluated on the popular and challenging face detection benchmark, i.e., the WIDER FACE training and validation subsets, respectively, achieving AP of 0.942, 0.919 and 0.821 with the speed of 28FPS. This performance exceeds some existing SOTA algorithms, demonstrating acceptable accuracy and near real time detection for VGA resolution images, even in the complex scenarios. In addition, the proposed model shows good generation ability on another public dataset FDDB. The results indicate the proposed model is a promising face detector with high efficiency and accuracy in the wild.     

A Low-Cost 128 × 128 Uncooled Infrared Detector Array in CMOS Process

This paper discusses the implementation of a low-cost 128 times 128 uncooled infrared microbolometer detector array together with its integrated readout circuit (ROC) using a standard 0.35 mum n-well CMOS and post-CMOS MEMS processes. The detector array can be created with simple bulk-micromachining processes after the CMOS fabrication, without the need for any complicated lithography or deposition steps. The array detectors are based on suspended p⁺-active/n-well diode microbolometers with a pixel size of 40 mum times 40 mum and a fill factor of 44%. The p⁺-active/n-well diode detector has a measured dc responsivity (R) of 4970 V/W and a thermal time constant of 36 ms at 50 mtorr vacuum level. The total measured rms noise of the diode type detector is 0.69 muV for an 8 kHz bandwidth, resulting in a detectivity (D*) of 9.7 times 10⁸ cm ldr Hz^1/2/W. The array is scanned by an integrated 32-channel parallel ROC including low-noise differential preamplifiers with an electrical bandwidth of 8 kHz. The 128 times 128 focal plane array (FPA) has one row of infrared-blind reference detectors that reduces the effect of FPA fixed pattern noise and variations in the operating temperature relaxing the requirements for the temperature stabilization. Including the noise of the reference and array detectors together with the ROC noise, the fabricated 128 times 128 FPA has an expected noise equivalent temperature difference (NETD) value of 1 K for f/1 optics at 30 frames/s (fps) scanning rate. This NETD value can be decreased to 350 mK by improving the post-CMOS fabrication steps and increasing the number of readout channels.     

CZT像素核辐射探测器读出电路的设计

CZT作为一种新型室温核辐射探测器材料,适用范围广泛,设计一种有效的CZT读出电路意义重大。采用CMOS技术设计了一种高分辨率、低功耗的CZT像素核辐射探测器读出电路。该读出电路包括电荷敏感型前置运放、整形滤波网络、放大级。运放采用PMOS输入折叠共源共栅结构,滤波网络采用简单的RC—CR结构。在GPDK 0.18μm CMOS工艺下进行的仿真,表明该读出电路的灵敏度为0.3mV/keV,探测能量范围为20～200 keV,单信道功耗为1 mW。     

分布式远距离多点测温系统的开发与应用

介绍了远距离多点测温系统的软、硬件的开发;通过单总线实现多点温度的采集,通过总线驱动实现远距离的温度采集,通过上位机和现场测温模块的配合搭建了分布式的远距离多点测温监控系统.     

Realization of FTA with High Tracking Accuracy in FSO

High tracking accuracy is a prerequisite of reliable space optical communication links and its effective means is the utilization of coarse and fine compound‐axis structure. After an in‐depth study of the active laser tracking mechanism of fine tracking assembly, this paper emphasizes the exploration of these methods enabling the improvement of tracking accuracy under the condition of relative movement and platform vibration. Firstly, switching technique using a single beacon between different divergence angles is put forward to improve the signal to noise ratio (SNR) of the focal spot. Secondly, the high‐frame rate charge‐coupled device is achieved after proposing the pseudo random window readout technique. Thirdly, the unique design of the high resonant frequency of two‐dimensional PZT fast steering mirror (FSM) and sub‐pixel subdivision technique with adaptive control of integral time is used to achieve high accuracy and fast beam pointing. Fourthly, this paper puts forward a digital servol control method with intelligent variable structure. Finally, after building a hardware‐in‐loop simulation platform, the tracking accuracy of 3μrad is concluded according to simulation experimental results.     

High performance human information sensor

High performance human information sensing system, which can monitor the human conditions in a room, especially the number of occupants, their locations and activities, has been developed. The sensor head module of this sensing system consists of a vertical one-dimensional 16-element array detector fabricated by sheet forming method of pyroelectric PbTiO₃ ceramics, an IR-transparent spherical lens, a horizontal scanning mechanical part and a cylindrical mechanical chopping part. The IR lens characteristics have been determined to optimize the sensor output. The sensor is able to detect a two-dimensional thermal distribution (16×60) and the human condition information in a room. The sensor is cost-effective and the sensor head module is small (64 mm in diameter and 79 mm in height) with high resolution. Furthermore, nine times higher resolution with 48×180 thermal distribution was accomplished by the neighbor output averaging scheme. By using this sensing system with high sensitivity and high resolution, the small thermal object such as a lighted cigarette as well as the number of persons in a room can be detected accurately.     

AN ANALYTICAL DEVELOPMENT OF A UNIVERSAL DISPLACEMENT MEASUREMENT SYSTEM FOR ULTRA-PRECISION METROLOGY

In recent years, precise metrology up to nanoscale has attracted substantial attention due to an increasing need for ultra-precision measurement systems for micro electro mechanical systems (MEMS) and nano electro mechanical systems (NEMS) calibration. In this paper, an analytical and numerical investigation for the proposed design of a 6-degree-of-freedom (6-dof) universal measurement system, using a relatively simple and inexpensive but highly sensitive set up, is presented. This system utilizes a convex mirror and two flat mirrors, one angled and one vertical, as targets to reflect laser beams onto photo detectors. These targets, placed on the object of interest for metrology applications, change the direction of the reflected beam when there is any movement in the object, which is detected by the photo detectors. The use of convex and angled mirrors greatly enhances the sensitivity of the system. Geometric relationships are established among all the optical components to predict the final intersection points of the laser beams reflected from the targets with the photo detector planes. These relationships are used to establish a Jacobian partial derivative matrix, which is further used to estimate the target pose when the photo detector outputs are given. Numerical simulation of the measurement process is performed using MATLAB®. Assuming the approximate distance from laser beam origin to target and the target to photo detector as 50 mm, and photo detector resolution as 0.1 µm, translations and rotations less than 50 nm and 2 arc sec, respectively, can be measured accurately. The highest amount of sensitivity in translation is obtained along the Z-axis with minimum a measurement of 3.4 nm; the highest amount of sensitivity in rotation is along the pitch-axis with a minimum measurement of 0.145 arc sec. The corresponding low sensitivity axes are X-axis and yaw-axis, with minimum measurements of 35 nm and 2 arc sec, respectively. The sensitivity and the resolution of the system can be increased many times further by increasing the curvature of the convex mirror or by increasing the distance between the target and the detectors. The analytical and simulation results of this work yield a scientific and engineering guideline for the development of meso, micro, as well as nanoscale metrology systems.     

Key Points-based Indexing for Pre-attentive Similarities: The KIWI System

In this paper, we introduce the general architecture of an image-search engine based on pre-attentive similarities. Local features are computed in key points to represent local properties of the images. The location of key points, where local features are computed, is discussed. We present two new key point detectors designed for image retrieval, both based on multi-resolution: the contrast-based point detector, and the wavelet-based point detector. Four different local features are used in our system: differential invariants, texture, shape and colour. The local information computed in each key point is stored in 2D histograms to allow fast querying. We study the choice of the key points detector depending on the feature used, for different test sets. The Harris corner detector is used for benchmarking. Uniformly distributed points are also used, and we conclude for which applications they are effective. Finally, we show that point detector and feature efficiency depend upon the test set studied.