Abstract:针对毫米波电路对大电流、高截止频率器件的要求,利用平坦化技术,设计并制作成功了结构紧凑的四指合成InGaAs/InP异质结双极晶体管.实验结果表明发射极的宽度可减小到1μm.Kirk电流可达到110wA,电流增益截止频率达到176GI-Iz.这种器件有望在中等功率的毫米波电路中有所应用.

Abstract:Techniques of assembly,packaging and reliability of infrared focal plane array(IRFPA) were systematically studied.Some theoretic and technical problems were solved,such as the simulation of assembly conformation,high precision allocation of the modules,the design of flat leading wire,low leakage rate of laser welding,the way to decrease outgassing of Dewar inner surface.For the IRFPA detector the tests of assembly reliability,high-energy particle and laser irradiations were carried out.A batch of practical ...

Abstract:介绍了长波红外2048元线列碲镉汞焦平面器件的制备技术和达到的性能参数.探测器采用离子注入平面pn结制备光敏元,通过间接倒焊技术和读出电路互联,采用8个256元焦平面模块拼接2048元线列焦平面器件.光敏元的响应截止波长达到9.9μm,相应的RoA达到10Ωcm2,平均峰值探测率达到9.3×1010cmHz1/2 W-1,响应不均匀性为8%,有效光敏元率大干99.5%.

Abstract:The physical principle of laser induced breakdown spectroscopy(LIBS) was interpreted.How the pressure affects the laser induced plasma was analyzed.A LIBS experimental system for the low pressure condition was setup and the experiments at the different pressures were carried out.The experimental result expresses how the pressure affects the laser induced plasma quantitatively.The feasibility on the application of LIBS to lunar exploration was discussed.

Abstract:提出了基于lαβ颜色空间变换和小波包变换的红外中波细分波段图像的伪彩色增强方法.利用lαβ变换将两个细分波段RGB彩色映射的伪彩色图像的颜色和亮度信息分离,通过二维小波包变换得到两个细分波段的融合图像,将融合图像和颜色信息经过lαβ逆变换形成伪彩色增强图像.实验结果表明,同简单彩色映射图像相比,伪彩色增强图像的局部标准偏差和局部熵都有增加,从而使图像具有更好的感知效果.

Abstract:Dust aerosol can cause the change of the land surface temperature(LST) by altering the thermal infrared radiative transfer of earth-atmosphere system.The influence of different winter and summer dust aerosol optical depth(AOD) on thermal infrared brightness temperature(BT) and LST retrieval was systematically studied and the inversion results influenced by water vapor in the atmosphere and surface factor were also studied.Thermal infrared radiative transfer calculation indicates that 1.brightness temperatur...

Abstract:Noises and background produced by the absorption of water in spectra signal are the main interference for prediction accuracy of quantitative calibration in blood glucose noninvasive measurement.By utilizing wavelet transform,the spectra signal can be split into multi-scale approximation and detail component.According to uninformative variable elimination(UVE) criterion,it is possible to distinguish the high-scale approximation component which presents background and low-scale detail coefficients which pres...

Abstract:Infrared hollow fibers were developed for spectroscopic gas sensing.The hollow core fiber has a silver film and a dielectric film on its inner surface to enhance the reflection rate,and thus to low the transmission loss.The chemical silver mirror-reaction method and the liquid-phase coating technique were used to form the silver and the dielectric film.Low-loss properties were achieved from the visible to the mid-infrared wavelength regions by optimizing the dielectric material and the film thickness.The lo...

Abstract:A new method for FTIR spectral quantitative analysis was presented.The new method couples kernel partial least squares(KPLS) feature extraction with support vector regression machine(SVR) to improve the quantitative analysis accuracy and speed of seven-component alkane gas mixtures composed of methane,ethane,propane,iso-butane,n-butane,iso-pentane,and n-pentane,whose feature absorption spectra are cross each other and overlapped seriously.Firstly,the KPLS was employed to extract feature components from the ...

Abstract:Rough topographic data of granite surface were measured by atomic force microscope(AFM),and the characteristics of this real surface were analyzed according to the topographic data.In the range of geometric optics approximation,the bi-directional reflectance distribution function(BRDF) of this real surface was modeled by Monte Carlo method based on the surface topographic data,where the shadowing effect of incidence and the multiple reflections were considered.By comparing the modeling results of BRDF with ...

Abstract:Suspended matter concentration is an important parameter of water quality and water environment evaluation.The field experiments including water quality analysis and spectrum measurements were carried out in 74 stations of Lake Tai during 14 days from 8th Nov.2007 to 21th Nov.2007.After analyzing the correlations between remote sensing reflectance and suspended matter concentrations,the results show that remote sensing reflectance in the range of 400~900nm wave bands is highly and moderately related to tota...

Abstract:The object emissivity characteristics and the theory of heat radiation were studied to detect sand dust storm by remote sensing technique.The results show that the material nature of sand dust,ground surface and clouds is different when the sand dust happens.The ratio between the ground and sand dust in pixel images is different when the strength of sand dust changes.And these differences lead to the variations of material nature in pixels and object emissivity.At last,by a combination of theoretical and ex...

Abstract:Weakening the effect of heat island by environment construction is one of the key aspects for city development.To assure the reasonable planning of city construction,it is helpful analyzing the effect of land use types on ground heat distribution to get scientific data.In this study,by using Landsat ETM+ daytime remote sensing data of Shanghai,the inversion of ground bright temperature(GBT),the compose of color map and the classification of land use were made.On this basis,the relationships between daytime ...

Abstract:Polarization remote sensing is a new method with several advantages in detection.It is very important to study atmosphere and targets on the ground.To investigate the polarimetric scattering characteristics of camouflage targets,polarimetric parameters of three color pattern camouflage net were measured in visible and infrared waveband.By the analysis of data,it was found that polarimetric scattering characteristics of camouflage net were mainly influenced by incidence angle and reflectance of surface under...

Abstract:SVM model optimal multi-parameter selection method for imbalanced data recognition was proposed.First,the connotation and necessity of SVM model multi-parameter selection were theoretically analyzed.Then,a multi-parameter selection criterion based on F-measure was given,which can represent the recognition performance completely.The genetic algorithm was used in search of optimization of multi-parameter in parallel parameter optimal selection.The proposed method can get the global optimal solutions of SVM mo...

Abstract:In recent years,C-V model has been extensively used in image segmentation,but the computation speed is the key factor restricting the use of the method,especially for the large high resolution remote sensing imagery with complex scene,since the consuming time is very long.This research presented the method of combining C-V model and wavelet transform,which not only can improve the speed but also can achieve the multi-resolution segmentation,and has good anti-noise performance.Experiment results show that ou...

Abstract:When utilizing polarization remote sensing for earth observation,or atmosphere scattering,the polarization effect of atmosphere is always higher than the land surface's.It is usually believed that the polarization effect of the atmosphere is the main information resource of the remote sensing sensor.Thus the land surface's polarization is often ignored in remote sensing retrieval.This conclusion is based on the assumption that the reflection of land objects is diffuse reflection.However,in most cases,land o...

Abstract:A segmentation algorithm based on wavelet domain hidden Markov tree model was improved.The pixel level segmentation result can not be obtained because of choosing wavelet coefficients as training feature directly in traditional methods.At the same time,traditional methods ignore the feature of labeling maps at different scales by using one single context to all scales in fusion phase.Hence,this study dealt with the initial parameters set problem and chose better feature for training.In this way,the fine pix...