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Displacement measuring grating interferometer: a review Special Feature on Precision Measurement and Inst

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

Frontiers of Information Technology & Electronic Engineering 2019, Volume 20, Issue 5,   Pages 631-654 doi: 10.1631/FITEE.1800708

Abstract:

A grating interferometer, called the “optical encoder,” is a commonly used tool for precise displacement measurements. In contrast to a laser interferometer, a grating interferometer is insensitive to the air refractive index and can be easily applied to multi-degree-of-freedom measurements, which has made it an extensively researched and widely used device. Classified based on the measuring principle and optical configuration, a grating interferometer experiences three distinct stages of development: homodyne, heterodyne, and spatially separated heterodyne. Compared with the former two, the spatially separated heterodyne grating interferometer could achieve a better resolution with a feature of eliminating periodic nonlinear errors. Meanwhile, numerous structures of grating interferometers with a high optical fold factor, a large measurement range, good usability, and multidegree-of-freedom measurements have been investigated. The development of incremental displacement measuring grating interferometers achieved in recent years is summarized in detail, and studies on error analysis of a grating interferometer are briefly introduced.

Keywords： Grating interferometer     Optical encoder     Displacement measurement     Precision measurement    

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Fused-like angles: replacement for roll-pitch-yaw angles for a six-degree-of-freedom grating interferometer Research Article

Di Chang, Pengcheng Hu, Jiubin Tan,di.chang@hit.edu.cn,hupc@hit.edu.cn,jbtan@hit.edu.cn

Frontiers of Information Technology & Electronic Engineering 2021, Volume 22, Issue 12,   Pages 1551-1684 doi: 10.1631/FITEE.2000432

Abstract: is important in a six-degree-of-freedom but only a few studies have focused on this topic. Roll-pitch-yaw angles, widely used in aviation, navigation, and robotics, are now being brought to the field of multi-degree-of-freedom interferometric measurement. However, the roll-pitch-yaw angles are not the exact definitions the metrologists expected in interferometry, because they require a certain sequential order of rotations and may cause errors in describing complicated rotations. The errors increase as the tip and tilt angles of the grating increase. Therefore, a replacement based on fused angles in robotics is proposed and named “.” The are error-free, so they are more in line with the definitions in grating interferometry and more suitable for s. have already been used in research on the kinematic model and decoupling algorithm of the six-degree-of-freedom .

Keywords： 无偏溯源角；光栅干涉仪；六自由度测量；角度表达方法    

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Dual-Comb Ranging Review

Zebin Zhu, Guanhao Wu

Engineering 2018, Volume 4, Issue 6,   Pages 772-778 doi: 10.1016/j.eng.2018.10.002

Abstract:

Absolute distance measurement is a fundamental technique in mobile and large-scale dimensional metrology. Dual-comb ranging is emerging as a powerful tool that exploits phase resolution and frequency accuracy for high-precision and fast-rate distance measurement. Using two coherent frequency combs, dual-comb ranging allows time and phase response to be measured rapidly. It breaks through the limitations related to the responsive bandwidth, ambiguity range, and dynamic measurement characteristics of conventional ranging tools. This review introduces dual-comb ranging and summarizes the key techniques for realizing this ranging tool. As optical frequency comb technology progresses, dualcomb ranging shows promise for various professional applications.

Keywords： Ranging     Dual-comb interferometer     Phase noise     Timing jitter     Tight-locking     Post-correction    

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A general method of designing phase-shifting algorithms for grating lateral shearing interferometry None

Chao FANG, Yang XIANG, Ke-qi QI

Frontiers of Information Technology & Electronic Engineering 2018, Volume 19, Issue 6,   Pages 809-814 doi: 10.1631/FITEE.1601692

Abstract: We propose a general method of designing phase-shifting algorithms for grating lateral shearing interferometry. The algorithms compensate for the zeroth-order effect error and phase-shifting error in varying degrees. We derive a general expression of the phase-shifting algorithm in grating lateral shearing interferometer and introduce the corresponding design method. Based on the expression and method, four phase-shifting algorithms are designed with different phase-shifting errors to obtain high measurement accuracy. A new 13-frame phase-shifting algorithm is designed and simulated with a large zeroth-order effect. Simulation results verify the general expression and the corresponding design method.

Keywords： Interferometry     Phase measurement     Phase-shifting algorithms    

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Rapid thermal sensors with high resolution based on an adaptive dual-comb system Special Feature on Precision Measurement and Inst

Yi-zheng GUO, Ming YAN, Qiang HAO, Kang-wen YANG, Xu-ling SHEN, He-ping ZENG

Frontiers of Information Technology & Electronic Engineering 2019, Volume 20, Issue 5,   Pages 674-684 doi: 10.1631/FITEE.1800347

Abstract:

We report a high-resolution rapid thermal sensing based on adaptive dual comb spectroscopy interrogated with a phase-shifted fiber Bragg grating (PFBG). In comparison with traditional dual-comb systems, adaptive dual-comb spectroscopy is extremely simplified by removing the requirement of strict phase-locking feedback loops from the dual-comb configuration. Instead, two free-running fiber lasers are adopted as the light sources. Because of good compensation of fast instabilities with adaptive techniques, the optical response of the PFBG is precisely characterized through a fast Fourier transform of the interferograms in the time domain. Single-shot acquisition can be accomplished rapidly within tens of milliseconds at a spectral resolution of 0.1 pm, corresponding to a thermal measurement resolution of 0.01 °C. The optical spectral bandwidth of the measurement also exceeds 14 nm, which indicates a large dynamic temperature range. It shows great potential for thermal sensing in practical outdoor applications with a loose self-control scheme in the adaptive dual-comb system.

Keywords： Interferometers     Fiber sensors     Laser spectroscopy    

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Effects of residual motion compensation errors on the performance of airborne along-track interferometric SAR Article

Hui ZHANG,Jun HONG,Xiao-lan QIU,Ji-chuan LI,Fang-fang LI,Feng MING

Frontiers of Information Technology & Electronic Engineering 2016, Volume 17, Issue 10,   Pages 1095-1106 doi: 10.1631/FITEE.1500311

Abstract: Two approximations, center-beam approximation and reference digital elevation model (DEM) approximation, are used in synthetic aperture radar (SAR) motion compensation procedures. They usually introduce residual motion compensation errors for airborne single-antenna SAR imaging and SAR interferometry. In this paper, we investigate the effects of residual uncompensated motion errors, which are caused by the above two approximations, on the performance of airborne along-track interferometric SAR (ATI-SAR). The residual uncompensated errors caused by center-beam approximation in the absence and in the presence of elevation errors are derived, respectively. Airborne simulation parameters are used to verify the correctness of the analysis and to show the impacts of residual uncompensated errors on the interferometric phase errors for ATI-SAR. It is shown that the interferometric phase errors caused by the center-beam approximation with an accurate DEM could be neglected, while the interferometric phase errors caused by the center-beam approximation with an inaccurate DEM cannot be neglected when the elevation errors exceed a threshold. This research provides theoretical bases for the error source analysis and signal processing of airborne ATI-SAR.

Keywords： Synthetic aperture radar (SAR)     Along-track interferometric     Motion compensation     Residual error     Interferometric phase    

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Innovative Scanners Boost Medical Imaging Quality and Utility

Mitch Leslie

Engineering 2022, Volume 16, Issue 9,   Pages 3-5 doi: 10.1016/j.eng.2022.07.005

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Analysis and research on extending lifespan technology of FY-3 microwave radiation imager

Liu Gaofeng,Chen Weiying,Weng Yihang,Yu Shuang and Wang Hua

Strategic Study of CAE 2013, Volume 15, Issue 7,   Pages 101-105

Abstract:

Considering the characteristics of Fengyun-3(FY-3) satellite lifespan on orbit increased from 3 years to 5 years, the risk of extending lifespan was analyzed, and the reliability of scan driver system and receiver system which were critical items of microwave radiation imager was evaluated, taking corresponding measures from design and improving crafts reliability. Microwave radiation imager operates normally on orbit and provides effective reliability assurance according to these methods. Finally, the ideal of accelerated lifespan test was put forward at last.

Keywords： microwave radiation imager     scan driver     receiver     lifespan     reliability    

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Precise Three-Dimensional Deformation Retrieval in Large and Complex Deformation Areas via Integration of Offsets-Based Unwrapping and Improved Multiple-Aperture SAR Interferometry: Application to the 2016 Kumamoto Earthquake Article

Won-Kyung Baek, Hyung-Sup Jung

Engineering 2020, Volume 6, Issue 8,   Pages 927-935 doi: 10.1016/j.eng.2020.06.012

Abstract:

Conventional synthetic aperture radar (SAR) interferometry (InSAR) has been successfully used to precisely measure surface deformation in the line-of-sight (LOS) direction, while multiple-aperture SAR interferometry (MAI) has provided precise surface deformation in the along-track (AT) direction. Integration of the InSAR and MAI methods enables precise measurement of the two-dimensional (2D) deformation from an interferometric pair; recently, the integration of ascending and descending pairs has allowed the observation of precise three-dimensional (3D) deformation. Precise 3D deformation measurement has been applied to better understand geological events such as earthquakes and volcanic eruptions. The surface deformation related to the 2016 Kumamoto earthquake was large and complex near the fault line; hence, precise 3D deformation retrieval had not yet been attempted. The objectives of this study were to ① perform a feasibility test of precise 3D deformation retrieval in large and complex deformation areas through the integration of offset-based unwrapped and improved multiple-aperture SAR interferograms and ② observe the 3D deformation field related to the 2016 Kumamoto earthquake, even near the fault lines. Two ascending pairs and one descending the Advanced Land Observing Satellite-2 (ALOS-2) Phased Array-type L-band Synthetic Aperture Radar-2 (PALSAR-2) pair were used for the 3D deformation retrieval. Eleven in situ Global Positioning System (GPS) measurements were used to validate the 3D deformation measurement accuracy. The achieved accuracy was approximately 2.96, 3.75, and 2.86 cm in the east, north, and up directions, respectively. The results show the feasibility of precise 3D deformation measured through the integration of the improved methods, even in a case of large and complex deformation.

Keywords： Synthetic Aperture Radar (SAR)     Conventional SAR interferometry (InSAR)     Multiple-aperture SAR interferometry (MAI)     ALOS2 PALSAR2     3D deformation retrieval     2016 Kumamoto earthquake    

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A digital moiré fringe method for displacement sensors Article

Jian WU,Ting-ting ZHOU,Bo YUAN,Li-qiang WANG

Frontiers of Information Technology & Electronic Engineering 2016, Volume 17, Issue 9,   Pages 946-953 doi: 10.1631/FITEE.1500270

Abstract: In this study, a displacement measurement method based on digital moiré fringe is described and experimentally demonstrated. The method is formed by only one grating with a constant pitch. First, the magnified grating image is received by an imaging array and is sent to a computer. Then, the digital moiré fringes are generated by overlaying the grating image with its mirrored one. Finally, a specifically designed algorithm is used to obtain the fringes’ phase difference before and after movement and calculate the displacement. This method has the effects of amplifying displacement and averaging the grating lines error, the same as the traditional moiré technique using two pieces of gratings. At the same time, the proposed system is much easier to assemble and the measurement resolution can be set more flexibly. One displacement measuring system based on this method was built up. Experiment results show that its measurement errors are less than 0.3 μm and less than 0.12 μm at the resolutions of 0.1 μm and 0.03 μm, respectively.

Keywords： Digital moiré     fringe     Displacement measurement     Grating    

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Antenna design and analysis of Fengyun-3 microwave humidity sounder

Wang Hongjian,Li Jing,Liu Heguang,Zhang Shengwei

Strategic Study of CAE 2009, Volume 11, Issue 4,   Pages 39-45

Abstract:

Fengyun-3(FY-3) microwave humidity sounder antenna has the following specialties: high gain, low noise, high beam efficiency and high frequency. This Antenna has great influence on the precision of the whole system of FY-3MHS (microwave humidity sounder), offset parabolic antennae with conical corrugated horns are selected for these antennae. The frequencies of the antenna are 150 GHz and 183 GHz respectively (up to the highest frequency of the payload for the domestic satellite ), in addition, dual linear polarizations are also needed for the 150 GHz channels. Great challenges are brought about with the stringent demand for the FY-3MHS antenna. The analysis and design of this antenna need intercross knowledge of the electromagnetic theory, mechanics, manufacturing, measurements, quasi-optics, thermal and orbit etc. The successful design and assembly of FY-3MHS antennae fill up the gap of remote sensing in our country and stride a greatly leap in antenna theory.

Keywords： FY-3MHS     offset parabolic antenna     corrugated horn     remote sensing    

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Adaptive Wavelet Thresholding Denoising Used in Gravitational Signal Processing

Zhao Liye,Zhou Bailing,Li Kunyu

Strategic Study of CAE 2006, Volume 8, Issue 3,   Pages 49-52

Abstract:

The theory of wavelet thresholding denoising is analyzed and applied to process the data measured by gravimeter in order to effectively alleviate the effect of different noise in high precise gravitational system. The signal to noise ration (SNR) is used as the index for evaluating the performance of the data processing methods. Theoretical analysis and emulation experiments indicate that wavelet thresholding denoising, adaptive wavelet thresholding denoising and adaptive Kalman filtering are all effective in alleviating the effects of different noise, but the performance of adaptive wavelet thresholding denoising is best.

Keywords： gravimeter     signal processing     wavelet transform     adaptive wavelet threshold     adaptive Kalman     filering    

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Lunar surface physical temperature retrieved from the measurements by CE-1 lunar microwave sounder

Li Yun,Jiang Jingshan,Wang Zhenzhan,Zhang Dehai and Zhang Xiaohui

Strategic Study of CAE 2013, Volume 15, Issue 7,   Pages 106-112

Abstract:

In this paper, algorithms of retrieving physical temperature and effective temperature from CE-1 lunar microwave sounder (CELMS) brightness temperatures are developed. The influences of physical temperature on microwave radiation are analyzed. These retrievals provide important information for evaluating other lunar surface parameters.

Keywords： CELMS     lunar surface physical temperature     retrieve    

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Study on Lighting Structure of Interactive Globe

Guo Yangkuan,Li Yinghui,Xu Wei,Xiong Qi,Ma Jing,Wang Yong,Song Yu

Strategic Study of CAE 2007, Volume 9, Issue 5,   Pages 50-52

Abstract:

Stated the principle of the talking globe, the lighting structure of the globe was studied,  and so were clear lighting for capitals,  diode's distribution,  and resolving power.  Then the talking globe was manufactured successfully. The method used in the article give a path for solving such problems.

Keywords： talking globe     structure design     resolving power     tube for bounding light     clear lighting    

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Hardware Module of Multi-Protocol Tester Based on the Specification of 2.0 Mb/s High Speed Signalling link

Liu Zhihui

Strategic Study of CAE 2002, Volume 4, Issue 2,   Pages 79-85

Abstract:

Great progress has been made in the information industry of the world. Protocol and signalling are becoming more and more important. Telecommunication equipments and instruments are the very guarantee for information industry. Following the development of mobile communication and intelligence network, the 64 kb/s No.7 signalling link now used is no longer suitable for the service increasement. The 2.048Mb/s high speed signalling link has become the best substitude. Since there is no related protocol testing equipment used for telecommunication branch, The 2.048 Mb/s high speed signalling protocol-analyzing set is developed for this purpose. In order to ensure the quality of the analyzing set, the best embedded processor and newest real time operating system are employed.

Keywords： 2.048 Mb/s high speed signalling link     embedded processor     real time operating system     protocol-analyzing set    

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Title Author Date Type Operation

Displacement measuring grating interferometer: a review

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

Journal Article

Fused-like angles: replacement for roll-pitch-yaw angles for a six-degree-of-freedom grating interferometer

Di Chang, Pengcheng Hu, Jiubin Tan,di.chang@hit.edu.cn,hupc@hit.edu.cn,jbtan@hit.edu.cn

Journal Article

Dual-Comb Ranging

Zebin Zhu, Guanhao Wu

Journal Article

A general method of designing phase-shifting algorithms for grating lateral shearing interferometry

Chao FANG, Yang XIANG, Ke-qi QI

Journal Article

Rapid thermal sensors with high resolution based on an adaptive dual-comb system

Yi-zheng GUO, Ming YAN, Qiang HAO, Kang-wen YANG, Xu-ling SHEN, He-ping ZENG

Journal Article

Effects of residual motion compensation errors on the performance of airborne along-track interferometric SAR

Hui ZHANG,Jun HONG,Xiao-lan QIU,Ji-chuan LI,Fang-fang LI,Feng MING

Journal Article

Innovative Scanners Boost Medical Imaging Quality and Utility

Mitch Leslie

Journal Article

Analysis and research on extending lifespan technology of FY-3 microwave radiation imager

Liu Gaofeng,Chen Weiying,Weng Yihang,Yu Shuang and Wang Hua

Journal Article

Precise Three-Dimensional Deformation Retrieval in Large and Complex Deformation Areas via Integration of Offsets-Based Unwrapping and Improved Multiple-Aperture SAR Interferometry: Application to the 2016 Kumamoto Earthquake

Won-Kyung Baek, Hyung-Sup Jung

Journal Article

A digital moiré fringe method for displacement sensors

Jian WU,Ting-ting ZHOU,Bo YUAN,Li-qiang WANG

Journal Article

Antenna design and analysis of Fengyun-3 microwave humidity sounder

Wang Hongjian,Li Jing,Liu Heguang,Zhang Shengwei

Journal Article

Adaptive Wavelet Thresholding Denoising Used in Gravitational Signal Processing

Zhao Liye,Zhou Bailing,Li Kunyu

Journal Article

Lunar surface physical temperature retrieved from the measurements by CE-1 lunar microwave sounder

Li Yun,Jiang Jingshan,Wang Zhenzhan,Zhang Dehai and Zhang Xiaohui

Journal Article

Study on Lighting Structure of Interactive Globe

Guo Yangkuan,Li Yinghui,Xu Wei,Xiong Qi,Ma Jing,Wang Yong,Song Yu

Journal Article

Hardware Module of Multi-Protocol Tester Based on the Specification of 2.0 Mb/s High Speed Signalling link

Liu Zhihui

Journal Article