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Airborne sparse flight array SAR 3D imaging based on compressed sensing in frequency domain

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Journal of Systems Engineering and Electronics 2023年第1期34卷 56-67页

作者： TIAN He DONG Chunzhu YIN Hongcheng YUAN Li Science and Technology on Electromagnetic Scattering Laboratory Bejing Insititute of Environment FeaturesBeijing 100854China

In airborne array synthetic aperture radar(SAR), the three-dimensional(3D) imaging performance and cross-track resolution depends on the length of the equivalent array. In this paper, Barker sequence criterion is used for sparse flight sampling of airborne array SAR, in order to obtain high cross-track resolution in as few times of flights as possible. Under each flight, the imaging algorithm of back projection(BP) and the data extraction method based on modified uniformly redundant arrays(MURAs) are utilized to obtain complex 3D image pairs. To solve the side-lobe noise in images, the interferometry between each image pair is implemented, and compressed sensing(CS) reconstruction is adopted in the frequency domain. Furthermore, to restore the geometrical relationship between each flight, the phase information corresponding to negative MURA is compensated on each single-pass image reconstructed by CS. Finally,by coherent accumulation of each complex image, the high resolution in cross-track direction is obtained. Simulations and experiments in X-band verify the availability.

关键词： three-dimensional(3D)imaging synthetic aperture radar(SAR) sparse flight interferometry compressed sensing(CS)

A New Approach of Quantum Mechanics for Neutron Single-Slit Diffraction

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Chinese Physics Letters 2007年第7期24卷 1813-1816页

作者：吴向尧杨景海刘晓静王丽刘兵范希会郭义庆 Institute of Physics 3ilin Normal University Siping 136000 Department of Physics Qufu Normal University Qufu 273165 Institute of High Energy Physics PO Box 918(3) Chinese Academy of Sciences Beijing 100049

Phenomena of electron, neutron, atomic and molecular diffraction have been studied in many experiments, and these experiments are explained by many theoretical works. We study neutron single-slit diffraction with a quantum mechanical approach. It is found that the obvious diffraction patterns can be obtained when the single- slit width a is in the range of 3λ - 60λ. We also lind a new quantum effect of the thickness of single-slit which can make a large impact on the diffraction pattern. The new quantum effect predicted in our work can be tested by the neutron single-slit diffraction experiment.

关键词： interferometry

Problems on fabrication of computer-generated holograms for testing aspheric surfaces

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Chinese Optics Letters 2009年第1期7卷 70-73页

作者：马骏高志山朱日宏何勇陈磊李建欣潘裕斌 W.H.Wong 黄立辉谢常青朱效立马杰 Department of Optical Engineering Nanjing University of Science and Technology Department of Electronic Engineering City University of Hong KongKowloon Tang Key Laboratory of Nano-Fabrication and Novel Devices Integrated Technology Institute of MicroelectronicsChinese Academy of Sciences

Interferometric optical testing using computer-generated hologram （CGH） can give highly accurate measurement of aspheric surfaces has been proved. After the system is designed, a phase function is obtained according to the CGH＇s surface plane. For the requirement of accuracy, an optimization algorithm that transfers the phase function into a certain mask pattern file is presented in this letter, based on the relationship between the pattern error of CGH and the output wavefront accuracy. Then the writing machine is able to fabricate such a mask with this kind of file. With that mask, an improved procedure on fabrication of phase type CGH is also presented. Interferometrie test results of an aspherie surface show that the whole test system obtains the demanded accuracy.

关键词： Computer generated holography Electron holography Holograms interferometry Masks Optical testing Probability density function

Comparison of L-band and X-band differential interferometric synthetic aperture radar for mine subsidence monitoring in central Utah

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International Journal of Mining Science and Technology 2017年第1期27卷 159-163页

作者： Jessica M.Wempen Michael K.McCarter Department of Mining Engineering University of UtahSalt Lake City 84112USA

Differential interferometric synthetic aperture radar(DIn SAR), a satellite-based remote sensing technique, has potential application for measuring mine subsidence on a regional scale with high spatial and temporal resolutions. However, the characteristics of synthetic aperture radar(SAR) data and the effectiveness of DIn SAR for subsidence monitoring depend on the radar band(wavelength). This study evaluates the effectiveness of DIn SAR for monitoring subsidence due to longwall mining in central Utah using L-band(24 cm wavelength) SAR data from the advanced land observing satellite(ALOS)and X-band(3 cm wavelength) SAR data from the Terra SAR-X mission. In the Wasatch Plateau region of central Utah, which is characterized by steep terrain and variable ground cover conditions, areas affected by longwall mine subsidence are identifiable using both L-band and X-band DIn ***, using L-band data, subsidence magnitudes are measurable. Compared to X-band, L-band data are less affected by signal saturation due to large deformation gradients and by temporal decorrelation due to changes in the surface conditions over time. The L-band data tend to be stable over relatively long periods(months). Short wavelength X-band data are strongly affected by signal saturation and temporal decorrelation, but regions of subsidence are typically identifiable over short periods(days). Additionally,though subsidence magnitudes are difficult to precisely measure in the central Utah region using X-band data, they can often be reasonably estimated.

关键词： Mine subsidence DInSAR Terra SAR-X ALOS interferometry

In vitro birefringence imaging with spectral domain polarization-sensitive optical coherence tomography

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Chinese Optics Letters 2008年第12期6卷 905-909页

作者：龚强范传茂张帆姚建铨 Key Laboratory of Optoelectric Information Science and Technology Ministry of Education Tianjin University Institute of Laser and Optoelectronics College of Precision Instrument and Optoelectronics EngineeringTianjin University

Spectral domain polarization-sensitive optical coherence tomography （SDPS-OCT） is a depth-resolved polarization-sensitive interferometry which integrates polarization optics into spectral domain optical co- herence tomography （SD-OCT）. This configuration can obtain birefringence information of samples and improve the imaging speed. In this paper, horizontally polarized light is used to replace natural light of the source. Then, right-rotated circularly polarized light is the incident sample light. To obtain two orthogonal components of the polarized interferogram, the reflected light of the reference arm is set to be 45° linearly polarized light. These two components are acquired by two spectrometers synchronously. The system was employed to achieve 12.8μm axial resolution and 4.36μm transverse resolution. We have imaged in vitro chicken tendon and muscle tissues with these svstem.

关键词： Birefringence Capillary flow Coherent light Diagnostic radiography interferometry Light polarization Medical imaging Optical properties Optical tomography Polarization Strain measurement Tendons Tomography

Radiation-induced effects in polarization-maintaining optical fibers for interferometric gyroscope

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Chinese Optics Letters 2011年第6期9卷 21-23页

作者：王学勤张春熹金靖宋凝芳 Institute of Optics and Electronics Beihang University

Radiation-induced attenuation （RIA） in four types of polarization-maintaining optical fibers for interfer-ometric fiberoptic gyroscope （IFOG） at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60 Co source in order to observe significantly different RIA behavior and recovery kinetics. Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG. Medium-accuracy IFOG using Ge–F-codoped fiber and pure silica core fiber can survive in the space radiation environment.

关键词： Doping (additives) Fiber optic sensors Germanium Gyroscopes interferometry Optical fibers Polarization Radiation effects Silica

Superluminal Radio Source PKS 0420-014

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Chinese Physics Letters 1998年第7期15卷 545-546页

作者： HONG Xiao-yu JIANG Dong-rong SHEN Zhi-qiang WAN Tong-shan Shanghai Observatory Chinese Academy of SciencesShanghai 200030

The very long baseline interferometry result of a superluminal radio source PKS 0420-014 at 5 GHz with Shanghai(China),Urumqi(China),Noto(Italy),and HartRAO(South Africa)telescopes is *** motions of the relativistic jet components in the source are *** on the Self-Compton emission in a uniform spherical model,the beaming parameters of the source are *** results show that PKS 0420-014 has a high Doppler factor of 9.3,a Lorentz factor of 6.5,and a small angle of 5.5°to the line of sight.

关键词： interferometry relativistic Lorentz

A Fast Melting Release Method in Free-Fall Equivalence Principle Test

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Chinese Physics Letters 2001年第2期18卷 172-174页

作者： WU Zi-Gang WANG Dian-Hong LUO Jun ZHOU Ze-Bing NIE Yu-Xin ZHANG Yuan-Zhong Department of Physics Huazhong University of Science and TechnologyWuhan 430074 Department of Mechanical and Electronic Engineering China University of GeosciencesWuhan 430074 Institute of Physics Chinese Academy of SciencesBeijing 100080 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

A fast melting release method for the free-fall equivalence principle test using laser interferometry is *** primary experiment result shows that the uncertainty of the differential release time could be controlled at... 详细信息

关键词： release satis interferometry

Time-Domain Smoothing Processing for Equivalence-Principle Test Using Free-Fall Method

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Chinese Physics Letters 2005年第7期22卷 1614-1617页

作者：周泽兵王世芳罗俊 DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074

We investigate the effect of the time-domain smoothing processing for theequivalence-principle test using the free falling method, compared to the low-pass-filter *** calculation shows that the time-domain smoothing processing can suppress thehigh-frequency noises and does not cause pseudo-acceleration. The physical reason is that thetime-domain smooth-processing method is an unweighted filtering and is unrelated to the polynomialfitting. The uncertain acceleration difference due to high-frequency mechanical vibrations in theequivalence-principle test for extended rotating bodies can be suppressed from 2 mu Gal to 0.05 muGal after the time-domain smoothing processing.

关键词： interferometry BODIES