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Velocity estimation of moving targets for spaceborne multichannel synthetic aperture radar systems based on equivalent along-track interferometry technique

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IET RADAR SONAR AND NAVIGATION 2018年第9期12卷 964-972页

作者： Ding, Chibiao Jin, Tingting Qiu, Xiaolan Hu, Donghui Chinese Acad Sci Inst Elect Key Lab Technol Geospatial Informat Proc & Applic Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Velocity estimation of a moving target is an important yet challenging issue facing the special mode of high-resolution and wide-swath (HRWS) synthetic aperture radar. HRWS imaging is achieved by splitting the antenna into multiple receive channels in azimuth with each channel working at low pulse repetition frequency sampling. In this study, the authors propose a novel approach to estimate the velocity of a moving target in HRWS mode, along with a complete moving target indication, estimation, and imaging scheme. The proposed radial velocity estimation algorithm is called the equivalent along-track interferometry method, which is implemented by twice imaging after reconstructing the data of several leftmost and rightmost channels. Moreover, the along-track velocity is also estimated for focused imaging of the moving target. The motion-adapted reconstruction and imaging algorithm is applied to achieve unambiguous imaging of the moving target. Experimental results verify the performance of the algorithm and its superiority for a moving target with interference from clutter, noise, and channel mismatches. The proposed algorithm is free of search and iteration, and featured by high accuracy and low computational load.

关键词： radar imaging radar antennas synthetic aperture radar spaceborne radar image motion analysis image reconstruction radar clutter image sampling spaceborne multichannel synthetic aperture radar systems equivalent along-track interferometry technique HRWS imaging complete moving target indication radial velocity estimation algorithm equivalent along-track interferometry method motion-adapted reconstruction imaging algorithm high-resolution-and-wide-swath synthetic aperture radar multiple receive channels low pulse repetition frequency sampling complete moving target estimation complete moving target imaging scheme along-track velocity estimation channel mismatches

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Spaceborne Azimuth Multichannel BiSAR With Geosynchronous Transmitter and LEO Receiver: High-Resolution Wide-Swath Image Formation

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IEEE ACCESS 2019年 7卷 176291-176305页

作者： Wang, Yuekun Lu, Zheng Nanjing Res Inst Elect Technol Nanjing 210039 Peoples R China Beijing Inst Spacecraft Syst Engn Beijing 100094 Peoples R China

Spaceborne azimuth multichannel bistatic synthetic aperture radar (AMC-BiSAR) system employed inclined geosynchronous (GEO) transmitter and low-Earth-orbit (LEO) receiver is capable of providing a vast area of surveillance and fine spatial resolution, which presents great potentials for Earth observation. Nevertheless, owing to complex geometry and big differences of orbital characteristics, high-resolution wide-swath (HRWS) imaging for GEO-LEO AMC-BiSARs remains three major issues: 1) "Stop-and-Go'' approximation is invalid because of long round-trip delay and high receiver velocity;2) Due to the special bistatic configuration, the conventional effective phase center (EPC) operation for unambiguous signal reconstruction cannot be directly used;3) Two-dimension spatial-variant characteristics of the echo signal caused by nonlinear and nonparallel trajectories of transmitter and receiver raise challenges for BiSAR focusing. To address these problems, starting from modeling geometry of inclined GEO-LEO AMC-BiSAR, an accurate slant range model without "Stop-and-Go'' approximation is derived in the paper. Then the new effective positions of the receiving channels in GEO-LEO AMC-BiSARs are obtained based on the geometry, and the unambiguous Doppler spectrum can be recovered effectively. Finally, a nonlinear chirp scaling imaging algorithm based on the time-domain perturbation (TP-NLCS) is derived and presented, which can correct the variation of range cell migration and azimuth frequency modulation rate. Simulation results show the validity of the proposed method, which can implement GEO-LEO AMC-BiSAR HRWS focusing and has fine phase-preserved capability.

关键词： Geosynchronous (GEO) bistatic synthetic aperture radar (BiSAR) azimuth multichannel (AMC) high-resolution wide-swath (HRWS) imaging algorithm

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An imaging algorithm based on keystone transform for one-stationary bistatic SAR of spotlight mode

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EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2012年第1期2012卷 1页

作者： Qiu, Xiaolan Behner, Florian Reuter, Simon Nies, Holger Loffeld, Otmar Huang, Lijia Hu, Donghui Ding, Chibiao Chinese Acad Sci Inst Elect Beijing 100190 Peoples R China Chinese Acad Sci Key Lab Spatial Informat Proc & Appl Syst Beijing 100190 Peoples R China Univ Siegen Ctr Sensorsyst ZESS D-57076 Siegen Germany

This article proposes an imaging algorithm based on Keystone Transform for bistatic SAR with a stationary receiver. It can efficiently be applied to high-resolution spotlight mode, and can directly be process the bistatic SAR data which have been ranged compressed by the synchronization reference pulses. Both simulation and experimental results validate the good performance of this algorithm.

关键词： Bistatic SAR imaging algorithm Keystone transform

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A Novel Sub-Bottom Profiler and Signal Processor

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SENSORS 2019年第22期19卷 5052-5052页

作者： Tan, Cheng Zhang, Xuebo Yang, Peixuan Sun, Miao Aerodynam Res & Dev Ctr Aerosp Technol Inst CARDC Mianyang 621000 Sichuan Peoples R China Lab Underwater Acoust Zhanjiang 524000 Peoples R China Pan Wisdom Educ Lanzhou 730050 Gansu Peoples R China China Railway Twenty One Bur Grp Corp Lanzhou 730000 Gansu Peoples R China

In this paper, we introduce a novel sub-bottom profiler, making good use of the Mills cross configuration of multibeam sonar and synthetic aperture techniques of the synthetic aperture sonar system. The receiver array is mounted along the ship keel, while the transmitter array is mounted perpendicular to the receiver array. With the synthetic aperture technique, the along-track resolution can be greatly improved. The system often suffers from motion error, which severely degrades the imaging performance. To solve this problem, the imaging algorithm with motion compensation (MC) is proposed. With the presented method, the motion error is first estimated based on overlapped elements between successive pulses. Then, the echo data is processed by using the range migration algorithm based on the phase center approximation (PCA) method, which simultaneously performs the MC with the estimated motion error. In order to validate the proposed sub-bottom profiler and data processing method, some simulations and lake trial results are discussed. The processing results of the real data further indicate that the presented configuration has great potential to find buried objects in seabed sediments.

关键词： Mills cross configuration synthetic aperture technique motion compensation imaging algorithm

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AN EXPERIMENTAL ANALYSIS AND VALIDATION OF ELECTRICAL IMPEDANCE TOMOGRAPHY TECHNIQUE FOR MEDICAL OR INDUSTRIAL APPLICATION

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BIOMEDICAL ENGINEERING-APPLICATIONS BASIS COMMUNICATIONS 2019年第2期31卷

作者： Kumar, Ramesh Kumar, Sharvan Sengupta, A. Dr BR Ambedkar Natl Inst Technol Dept Instrumentat Control Engn Jalandhar Punjab India DA IICT Gandhinagar Gujarat India

Electrical impedance tomography is a recently established technique by which impedance of an object (medical or nonmedical applications) is measured data from the surface of the object, and a numerically simulated reconstruction of the object internal shape of the image can be obtained. This imaging technique based on boundary or surface voltage is measured when the different current pattern is injected into it. For current pulse, we are creating a voltage controlled current source, which is based on the different RC circuits, according to current amplitude and frequency values. The current source used in inject the current pulse of the various phantoms. The current position and measuring voltage is controlled by the created control unit or programmable system on chip (PSOC) of the proposed EIT system. After that image reconstruction of the cross-sectional image of resistivity requires sufficient data collection from used phantoms, which is based on finite element method (FEM) method and Tikhonov regularization method with helps of graphical user interface (GUI) on MatLab. The objective of the GUI was to produce an image (2D/3D), impedance distribution graph, and the FEM mesh model according to used electrode combinations from the various phantoms. EIT system has a great potential for imaging modality, is non-invasive, radiation-free, and inexpensive for medical applications.

关键词： Electrical impedance tomography Finite element method Tikhonov regularization Image reconstruction Medical Industrial Graphical user interface imaging algorithm

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A NOVEL HIGH-ORDER IMAGE FORMATION algorithm FOR GNSS-BASED BISTATIC SAR 38

A NOVEL HIGH-ORDER IMAGE FORMATION ALGORITHM FOR GNSS-BASED ...

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38th IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Zhou, Xin-Kai Wang, Peng-Bo Hu, Kai-Qi Zeng, Hong-Cheng Fang, Yue Chen, Jie Beihang Univ Sch Elect & Informat Engn Beijing Peoples R China

ISBN: (纸本)9781538671504

Global Navigation Satellite System (GNSS)-based bistatic Synthetic Aperture Radar (SAR) recently plays a more and more significant role in remote sensing applications for its low-cost, flexibility and real-time global coverage capability. In this paper, a novel high-order imaging algorithm is presented for GNSS-based bistatic SAR. Firstly, the modified equivalent squint range model (MESRM) is introduced to describe range history of the GNSS-based bistatic SAR, and the accuracy of the MESRM is analysed. Secondly, a high-order image formation algorithm based on the MESRM is derived, where the range cell migration (RCM) of the echo signal is corrected by two-step range cell migration correction (TSRCMC), and the azimuth-variance of the echo signal is solved by azimuth block hybrid correlation. Finally, simulation and experiment are performed to validate the presented algorithm.

关键词： Bistatic SAR imaging algorithm GNSS SAR signal processing

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Localization of fatigue cracks using low-frequency nonlinear Lamb waves in numerical perspective

Localization of fatigue cracks using low-frequency nonlinear...

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IEEE International Ultrasonics Symposium (IUS)

作者： Xu, Jichao Wei, Nuoke Zhu, Wujun Xiang, Yanxun Xuan, Fuzhen Deng, Mingxi East China Univ Sci & Technol Key Lab Pressure Syst & Safety MOD Sch Mech & Power Engn Shanghai 200237 Peoples R China Chongqing Univ Coll Aerosp Engn Chongqing 400044 Peoples R China

ISBN: (纸本)9781538634257

In this work, a probabilistic imaging algorithm based on ellipse method was carried out to locate a fatigue crack using nonlinear S0 mode Lamb waves, which was modeled by Three-dimensional (3D) Finite Element (FE) Simulation. A fatigue crack was modeled as a through thickness seam, and Short-time Fourier transform (STFT) was performed on the time-domain signals from FE model to extract temporal features. A damage index (DI) was built using a probabilistic imaging algorithm (PIA) after forming an ellipse-like locus. The ultimate image result showed that the location of the fatigue crack was identified and distinguished from the hole. In a conclusion, the proposed imaging algorithm would be a feasible and effective approach to locate fatigue crack by nonlinear S0 mode Lamb waves.

关键词： nonlinear S0 mode Lamb waves fatigue crack Finite Element (FE) Simulation imaging algorithm

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Imagery of Multiple Receiver SAS Based on Intel® Math Kernel Library 14

Imagery of Multiple Receiver SAS Based on Intel® Math Kerne...

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14th IEEE International Conference on Signal Processing (ICSP)

作者： Zhang, Xuebo Ying, Wenwei Tan, Cheng Dai, Xuntao Underwater Acoust Antagonizing Lab Zhanjiang 524022 Peoples R China Naval Res Acad Beijing 102249 Peoples R China China Aerodynam Res & Dev Ctr Computat Aerodynam Inst Mianyang 621000 Peoples R China Grp Corp 10 Res Inst Chengdu 610036 Sichuan Peoples R China

ISBN: (纸本)9781538646731

The focusing performance and the focusing efficiency are the two important issues for the multireceiver synthetic aperture sonar (SAS) system. Nowadays, the former one is not important any more as the performance of most imaging algorithms is more or less the same with each other. In other words, the latter one mostly limits the engineering application of the SAS system. In order to satisfy the real time processing of the multireceiver SAS data, the focusing method is usually developed by the parallel algorithm. In this paper, the Intel (R) math kernel library is used to develop the imaging algorithm, which can improve the focusing efficiency without loss of imaging performance. At last, the real data is used to demonstrate the presented method.

关键词： multiple receiver synthetic aperture sonar Intel (R) math kernel library imaging algorithm

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An Experimental Study on Microwave imaging of Breast Cancer with the use of Tumor Phantom

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APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL 2017年第10期32卷 941-947页

作者： Bicer, Mustafa B. Akdagli, Ali Mersin Univ Dept Elect & Elect Engn TR-33343 Mersin Turkey

Nowadays, breast cancer is the most common type of the cancer among women's diseases. It is the leading cause of death after cardiovascular diseases. Due to risk of uncontrolled reproduction and propagation of the cancer cells, early diagnosis has a crucial *** imaging (MWI) is an evolving method and has a variety of advantages such as operating at lower frequencies with a lower power, cost-effectiveness, and providing comfortable measurements without contact. In this paper, an experimental study on microwave imaging of breast cancer with the use of tumor phantom is presented. For this purpose, an experimental setup containing sand, screw and tumor phantom is prepared as replacement of real tissue. Two-dimensional inverse synthetic aperture radar (ISAR) method is used in handling the scattered electric field data from the measurement setup. Inverse radon transform (IRT) method is then utilized to extract the image of the measured scattering electric field data. The resultant images show that the microwave imaging method can be successfully used together with IRT for the breast cancer problem.

关键词： Breast cancer breast phantom imaging algorithm microwave imaging radar-based imaging

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imaging of Acute Appendicitis in Children

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JOURNAL OF PEDIATRIC INFECTIOUS DISEASES 2017年第1期12卷 48-60页

作者： Ferguson, Mark R. Wright, Jason N. Ngo, Anh-Vu Desoky, Sarah M. Iyer, Ramesh S. Univ Washington Seattle Childrens Hosp Sch Med Dept Radiol 4800 Sand Point Way NE Seattle WA 98105 USA Univ Arizona Coll Med Dept Radiol Tucson AZ 85724 USA

Acute appendicitis is a common cause of abdominal surgery in children, and is the result of appendiceal luminal obstruction and subsequent inflammation. The clinical presentation is often variable, allowing imaging to play a central role in disease identification and characterization. Ultrasound is often the modality of choice for diagnosis of appendicitis in children. Ready availability and lack of ionizing radiation are attractive features of sonography, though operator dependence is a potential barrier. Computed tomography (CT) was historically the preferred modality in children, as in adults, but recent awareness of the risks of radiation has reduced its usage. The purpose of this article is to detail the imaging findings of appendicitis in children. The discussion will focus on typical signs of appendicitis seen on ultrasound, CT, and magnetic resonance imaging. Considerations for percutaneous drainage by interventional radiology will also be presented. Finally, the evolution of imaging algorithms for appendicitis will be discussed.

关键词： appendicitis ultrasound CT MR interventional radiology drainage imaging algorithm appendectomy

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