Nonuniformly spaced array imaging

An image reconstruction algorithm for randomly spaced array imaging is developed. Based on the fact that the sampled bistatic Fourier space data can occupy almost the same region as that for rotating object imaging if the angular coverage is suitably defined, the range-Doppler reconstruction method developed in the rotating object imaging can be applied to the uniformly spaced circular array imaging case. When the array elements are randomly spaced, three more steps, a range alignment, a phase compensation, and an interpolation, are required to preprocess the measured signals. Experimental and numerical results have shown the effectiveness of the proposed algorithm     

红外CCD信号处理电路的设计

由于红外CCD的输出为高背景、宽动态范围的信号,所以在该信号的处理电路中,去除直流高背景和自动增益对于滤除背景噪声、提取目标信号必不可少．通过分析红外CCD信号处理电路的设计要求,介绍了应用于该信号处理的几种常用电路的设计方法．最后,着重阐述了基于CPLD(复杂可编程逻辑器件)和VSP3010的CCD信号处理电路的一体化设计方法．     

Yagi-Uda array for millimetre-wave imaging

An imaging array consisting of five Yagi-Uda antennas in a dielectric has been constructed for 50 GHz that has antenna patterns suitable for millimetre-wave applications. Crosstalk levels of less than -30 dB between adjacent antennas in an f/1.0 imaging array have been measured in 5 GHz model experiments.<>     

InSb charge-injection device imaging array

InSb CID arrays, in both 1 × 32 line and 16 × 24 two-dimensional format, have been successfully fabricated via a multilayer MIS processing technique. With the 1 × 32 line arrays, two-dimensional images were generated using a scanning mirror and a computer signal-conditioning technique. In this experiment the small temperature difference of a man's face was revealed. Two-dimensional, 16 × 24 area arrays have also been demonstrated in a staring mode by displaying real time raster-scanned IR images directly on a X-Y CRT monitor. The unprocessed IR video signal produced a sharp, clearly recognizable display with no sign of blooming, and exhibited excellent operating characteristics. Theoretical analysis showed that, at low sample rates, background limited performance (BLIP) can be obtained at background photon flux levels of as low as mid-10¹²photons/s . cm². The dominant noise source, in this case, is the integrated dark current shot noise. For operation at high sample rates, however, the bandwidth-dependent noise sources limit the array performance and, thus, BLIP occurs at higher background levels. The analysis has been confirmed by measured data on line arrays, resulting in good agreement between the theoretical curve and the experimental data.     

混成式热释电非制冷红外焦平面探测器研究

热释电非制冷红外焦平面探测器在军民领域具有广阔的应用前景.为了实现探测器的国内工程化研制,采用混成式技术,成功研制了基于锆钛酸铅(PZT)铁电陶瓷材料,像元尺寸为35 μm×35μm,列阵规模为320×240元的非制冷红外焦平面探测器.通过自主设计,研发的非制冷焦平面测试平台,得到了此器件的基本性能参数平均电压响应率1.1×105V/W,平均探测率5.6×107cm·Hz1/2·W-1,并实现了该探测器热成像.结合实际的研究工作,较为系统地介绍和讨论了热释电非制冷红外焦平面研制过程中各项关键技术.在器件光电响应测试数据分析的基础上,进一步提出下一阶段研究工作的重点和器件性能优化的方向.     

采用两维PtSi CCD的红外成像系统

本文描述了PtSi IRCCD的工作原理、性能、应用及与其它IRCCD器件的比较,着重阐述了采用两维PtSi IRCCD的红外热像仪的有关设计问题。     

超声相控阵中的成像技术

近年来,微电子和计算机技术领域的发展大大带动了超声信号的处理和图像重建技术的发展.现论述了超声相控阵成像研究的重要意义,描述了目前用于超声相控阵成像的技术,其中着重介绍了抽样相控阵技术这一新技术的原理和技术.     

802GHz integrated horn antennas imaging array

This short paper presents the pattern measurements at 802GHz of a single element in a 256-element integrated horn imaging array. The integrated-horn antenna consists of a dipole-antenna suspended on a 1μm dielectric membrane inside a pyramidal cavity etched in Silicon. The theoretical far-field patterns, calculated using reciprocity and Floquet-modes representation of the free-space field, agree well with the measured far-field patterns at 802GBz. The associated directivity for a 1.40 λ horn aperture, calculated from the measured E and H-plane patterns is 12.3dB±0.2dB. This work demonstrates that high-efficiency integrated-horn antennas are easily scalable to terahertz frequencies and could be used for radio-astronomical and plasma-diagnostic applications.     

提高IRCCD输出信号对比度的技术研究

结合制导中的高背景特性,本文对采用IRCCD器件导引头的制导系统,提出了一种采用光谱带宽优化以提高IRCCD器件输出信号对比度的方法。     

具有TDI读出模式的HgCdTe IRCCD的新发展

文章概述了时间延迟与积分的基本概念，典型结构，工作原理，以及上仍ＴＤＩ读出模式的混合式ＨｇＣｄＴｅ红外电荷器件的新发展和应用。     

Hybrid nonlinear moments in array processing and spectrum analysis

The aim of this paper is to provide a theoretical basis for the use of hybrid nonlinear (HNL) moments in array processing and spectrum analysis. These moments are defined as the expected value of the product of one random variable times a nonlinear function of another random variable. They generalize a class of twofold higher order moments, and their additional flexibility can be exploited for optimization purposes or for computational convenience. A number of properties beyond the classical Bussgang's (1952) and Price's (1958) theorems are found for HNL moments and matrices, making these statistics suitable for harmonic analysis and bearing estimation. Covariance based and higher order moments based methods are extended to the HNL moments domain, and a new class of Gaussian noise rejecting statistics is added to cumulants. The properties of some classes of matrices of HNL moments of practical interest are analyzed in detail     

A charge-coupled infrared imaging array with Schottky-barrier detectors

An IR sensitive, charge-coupled linear imaging array using palladium-silicide Schottky-barrier detectors has been designed, fabricated, and tested. Thermal scenes as low in temperature as 110/spl deg/C were imaged. It was shown theoretically that in the vidicon mode of operation, nonuniformities in the transfer process and in detector capacitance do not degrade the video signal. Good uniformity was indeed obtained in this mode. A scheme for removing the background signal from the detectors before loading into the charge-coupled device (CCD) was incorporated into the design of the chip, and operation in this mode was also demonstrated. This imager, though made with a single level of metallization with gaps, had reasonably good transfer efficiency and is free of smearing and blooming.     

微型多道成像光谱探测列阵的设计

介绍一种新颖的微型多道成像光谱分析系统用的控制列陈。通过对探测器工作原理分析，电路及传感器元件结构的优化设计，研制出５１２位象元自扫描光电二极管阵列的２００ｎｍ－１０００ｎｍ宽米谱响应的探测器，并给出了实验结果。     

Experimental performance of a thinned microwave imaging array

The performance of an experimentalX-band "quad" array imaging system is reported. The configuration has a physical aperture of only33 lambda, with 204 radiating elements and constitutes a basis for low cost real-time imaging.     

A charge-coupled infrared imaging array with Schottky-barrier detectors

An IR sensitive, charge-coupled linear imaging array using palladium-silicide Schottky-barrier detectors has been designed, fabricated, and tested. Thermal scenes as low in temperature as 110° C were imaged. It was shown theoretically that in the vidicon mode of operation, nonuniformities in the transfer process and in detector capacitance do not degrade the video signal. Good uniformity was indeed obtained in this mode. A scheme for removing the background signal from the detectors before loading into the charge-coupled device (CCD) was incorporated into the design of the chip, and operation in this mode was also demonstrated. This imager, though made with a single level of metallization with gaps, had reasonably good transfer efficiency and is free of smearing and blooming.     

可重构线阵图像制导信息处理机

以一种动态可一阵作为整体结构，同时把所有的接口与控制电路集成在几片现场可编程门阵列（ＦＰＧＡ）芯片中，实现了一种高性能红外图像制导处理机。在这个系统框架中高地 一些针对特定算法模块的专用处理器，如实现噪声白化和去除面目目标的单帧预处理器，单帧点目标粗检处理器等，这些处理器都能够集成在单片ＦＰＧＡ中，这种处理机具有模块化，接口标准化、结构灵活、易扩展的特点。     

Hybrid integration of GaAs-based VCSEL array with amorphous silicon sensor

We describe an optoelectronic module incorporating a vertical-cavity surface-emitting laser (VCSEL) array with a semitransparent light monitor. The power monitor is a p-i-n amorphous silicon photodetector fabricated on glass. Sets of micromachined springs for electrical contacting are also fabricated in the same process on the same glass substrate. Hybrid packages are formed by pressing the compliant springs against individual contact pads of the GaAs VCSEL array in a flip-chip assembly process. The light sensor is aligned directly on top of the laser elements. Most of the laser light is transmitted through the sensor, yet a large dynamic range is maintained because of the sensors exceedingly low dark current.     

Punch-through technique for charge collection in an extrinsic Si IRCCD

A compact punch-through charge collection structure, suitable for incorporation into an extrinsic silicon infra-red imaging CCD, is described. The operation of the structure is demonstrated using a 16-bit surface channel CCD fabricated in an n-epitaxial layer on an indium-doped substrate.     

Three-dimensional near-field MIMO array imaging using range migration techniques

This paper presents a 3-D near-field imaging algorithm that is formulated for 2-D wideband multiple-input-multiple-output (MIMO) imaging array topology. The proposed MIMO range migration technique performs the image reconstruction procedure in the frequency-wavenumber domain. The algorithm is able to completely compensate the curvature of the wavefront in the near-field through a specifically defined interpolation process and provides extremely high computational efficiency by the application of the fast Fourier transform. The implementation aspects of the algorithm and the sampling criteria of a MIMO aperture are discussed. The image reconstruction performance and computational efficiency of the algorithm are demonstrated both with numerical simulations and measurements using 2-D MIMO arrays. Real-time 3-D near-field imaging can be achieved with a real-aperture array by applying the proposed MIMO range migration techniques.     

Color imaging system using a single CCD area array

A color imaging system employing a single CCD sensor with a color filter array has been implemented. The system incorporates color channel enhancement and interpolation and provides display on a conventional color video monitor. Color correction matrix coefficients are computed. The response of the system is compared to that of a photographic film.