检索结果-内蒙古大学图书馆

An Efficient imaging algorithm for GNSS-R Bi-Static SAR

REMOTE SENSING 2019年第24期11卷 2945-2945页

作者： Zhou, Xin-kai Chen, Jie Wang, Peng-bo Zeng, Hong-cheng Fang, Yue Men, Zhi-rong Liu, Wei Beihang Univ Sch Elect & Informat Engn Beijing 100191 Peoples R China Univ Sheffield Dept Elect & Elect Engn Sheffield S1 4ET S Yorkshire England

Global Navigation Satellite System Reflectometry (GNSS-R) based Bi-static Synthetic Aperture Radar (BSAR) is becoming more and more important in remote sensing, given its low power, low mass, low cost, and real-time global coverage capability. Due to its complex configuration, the imaging for GNSS-R BSAR is usually based on the Back-Projection algorithm (BPA), which is very time consuming. In this paper, an efficient and general imaging algorithm for GNSS-R BSAR is presented. A Two Step Range Cell Migration (TSRCM) correction is firstly applied. The first step roughly compensates the RCM and Doppler phase caused by the motion of the transmitter, which simplifies the SAR data into the quasi-mono-static case. The second step removes the residual RCM caused by the motion of the receiver using the modified frequency scaling algorithm. Then, a cubic phase perturbation operation is introduced to equalize the Doppler frequency modulation rate along the same range cell. Finally, azimuth phase compensation and geometric correction are completed to obtain the focused SAR image. A simulation and experiment are conducted to demonstrate the feasibility of the proposed algorithm, showing that the proposed algorithm is more efficient than the BPA, without causing significant degradation in imaging quality.

关键词： GNSS-R SAR imaging algorithm TSRCM cubic phase perturbation

来源：评论

学校读者我要写书评

暂无评论

An imaging algorithm for Multireceiver Synthetic Aperture Sonar

引用

REMOTE SENSING 2019年第6期11卷 672-672页

作者： Zhang, Xuebo Tan, Cheng Ying, Wenwei Lanzhou Univ Technol Coll Elect & Informat Engn Lanzhou 730050 Gansu Peoples R China Lab Underwater Acoust Zhanjiang 524022 Peoples R China Computat Aerodynam Inst Aerodynam Res & Dev Ctr Mianyang 621000 Peoples R China Naval Res Acad Beijing 102249 Peoples R China

For the multireceiver synthetic aperture sonar (SAS), the point target reference spectrum (PTRS) in the two-dimensional (2D) frequency domain and azimuth modulation in the range Doppler domain were first deduced based on a numerical evaluation method and accurate time delay. Then, the difference between the PTRS and azimuth modulation generated the coupling term in the 2D frequency domain. Compared with traditional methods, the PTRS, azimuth modulation and coupling term was better at avoiding approximations. Based on three functions, an imaging algorithm is presented in this paper. Considering the fact that the coupling term is characterized by range variance, the range-dependent sub-block processing method was exploited to perform the decoupling. Simulation results showed that the presented method improved the imaging performance across the whole swath in comparison with existing multireceiver SAS processor. Furthermore, real data was used to validate the presented method.

关键词： synthetic aperture sonar (SAS) multireceiver numerical evaluation numerical transfer function imaging algorithm

来源：评论

学校读者我要写书评

暂无评论

Monopulse forward-looking imaging algorithm based on Levenberg-Marquardt optimisation

引用

JOURNAL OF ENGINEERING-JOE 2019年第20期2019卷 6593-6597页

作者： Zhou, Tao Pang, Bo Dai, Dahai Wu, Hao Wang, Xuesong Natl Univ Def Technol State Key Lab Complex Electromagnet Environm Effe Changsha Hunan Peoples R China

With precise angle measurement, traditional monopulse techniques for forward-looking imaging can acquire exact angle information of one single target within a radar beam. However, when multiple targets exist in a beam, it is difficult to resolve them. To address this problem, a novel monopulse forward-looking imaging algorithm based on Levenberg-Marquardt (LM) optimisation is proposed. The core idea of this algorithm is to solve maximum likelihood estimation problem based on LM optimisation (ML-LM) to obtain the direction of arrival (DOA) estimation of unresolved targets. First, the echo model of two targets within a forward-looking radar beam is established, then the imaging framework of the proposed algorithm is introduced. Finally, the advantages of ML-LM are illustrated based on a series of evaluation criterion, including angle measurement error for various values of signal-to-noise ratio (SNR), angle interval adaptability and computational efficiency. The simulation results show that two targets within a forward-looking radar beam can be resolved and relocated accurately utilising the proposed algorithm. Meanwhile, the comparison with other algorithms shows it has higher DOA estimation accuracy, less computational complexity and a wider range of angle interval adaptability.

关键词： angular measurement computational complexity maximum likelihood estimation target tracking measurement errors direction-of-arrival estimation radar imaging imaging algorithm Levenberg–Marquardt optimisation precise angle measurement traditional monopulse techniques exact angle information single target multiple targets novel monopulse maximum likelihood estimation problem LM optimisation ML-LM arrival estimation unresolved targets forward-looking radar beam imaging framework angle measurement error angle interval adaptability

来源：评论

学校读者我要写书评

暂无评论

Diffraction Tomographic imaging algorithm for Through-the-Wall Radar in Planar Multilayer Environment 13

Diffraction Tomographic Imaging Algorithm for Through-the-Wa...

引用

13th International Conference on Natural Computation, Fuzzy Systems and Knowledge Discovery (ICNC-FSKD)

作者： Qu, Lele Ge, Yanan Yang, Tianhong Zhang, Lili Shenyang Aerosp Univ Coll Elect Informat Engn Shenyang Liaoning Peoples R China

ISBN: (纸本)9781538621653

In order to solve the problem of imaging of concealed targets in planar multilayer environment, a novel diffraction tomographic (DT) imaging algorithm for through-the-wall radar (TWR) system is proposed in this paper. By exploiting the Born approximation (BA) theory, the spectral form of the Green function of the planar multilayered medium and exploding reflection model, the proposed DT imaging method can utilize the fast Fourier transform (FFT) technique to achieve the fast and accurate imaging reconstruction of targets hidden behind the multilayered wall. The imaging results reconstructed via the processing of synthetic data generated by finite-difference time-domain (FDTD) method have verified the validity and effectiveness of the proposed imaging method.

关键词： diffraction tomographic (DT) through-the-wall radar (TWR) planar multilayered wall imaging algorithm

来源：评论

学校读者我要写书评

暂无评论

Ground-Based SAR Wide View Angle Full-Field imaging algorithm Based on Keystone Formatting

引用

IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 2016年第6期9卷 2160-2170页

作者： Zeng, Tao Mao, Cong Hu, Cheng Tian, Weiming Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Beijing Key Lab Embedded Real Time Informat Proc Beijing 100081 Peoples R China

The interest of applying ground-based synthetic aperture radar (GB-SAR) in terrain displacement monitoring has increased for decades. Due to the large illuminating coverage and suitable working bandwidth, GB-SAR can achieve multitemporal surface deformation maps of the entire terrain with high spatial resolution and submilimetric accuracy. Unfortunately, focusing GB-SAR data in an efficient way is accompanied with a series of complicated engineering problems and should be solved. In this paper, a novel imaging algorithm tailored for GB-SAR data is proposed. First, the main characteristics of GB-SAR data are analyzed, and a signal model is then built up. Second, corresponding to this model, an imaging algorithm is put forward, which is based on keystone formatting and range-Doppler domain blocking. This algorithm is phase-preserving and can be widely applied in near-field, far-field, and wide view angle scenarios. Moreover, its computational cost is quite low, which includes only one time of linear interpolation and several times of fast Fourier transforms and complex multiplications. Finally, the algorithm is extensively validated both with numerical simulations and real GB-SAR data.

关键词： Ground-based SAR (GB-SAR) imaging algorithm keystone formatting subblock processing synthetic aperture radar (SAR)

来源：评论

学校读者我要写书评

暂无评论

Millimeter-wave LFMCW radar water surface detection experiment and its imaging algorithm

引用

Journal of Measurement Science and Instrumentation 2017年第1期8卷 46-53页

作者： CHONG Jin-song WEI Xiang-fei Institute o f Electronics Chinese Academy of Sciences Beijing 100190 China National Key Laboratory o f Science and Technology on Microwave Imaging Beijing 100190 China University o f Chinese Academy o f Sciences Beijing 100190 China

A millimeter-wave linear frequency modulated continuous wave(LFM CW)radar is applied to water surface *** paper presents the experiment and imaging *** imaging processing,water surface texture can hardly be seen in the results obtained by traditional imaging *** solve this problem,we propose a millimeter-wave LFMCW radar imaging algorithm for water surface *** from the traditional imaging algorithm,the proposed imaging algorithm includes two improvements as follows:Firstly,the interference from static targets is removed through a frequency domainfilter;Secondly,the multiplicative noises are reduced by the maximum likelihood estimation method,which is used to estimatethe azimuth spectrum parameters to calculate the energy of water surface *** results show that the proposed algorithmcan obtain water surface texture,which means that the proposed algorithm is superior to the traditional imaging algorithm.

关键词： millimeter-wave LFMCW radar water surface texture imaging algorithm maximum likelihood estimation

来源：评论

学校读者我要写书评

暂无评论

Feasibility analysis on the chirp scaling based wideband and wide swath synthetic aperture imaging algorithm 8

Feasibility analysis on the chirp scaling based wideband and...

引用

8th International Conference on Digital Image Processing (ICDIP)

作者： Lv Jinhua Tian Zhen Cheng Guangyu Hong Yong Wuhan Inst Shipbldg Technol Wuhan Peoples R China Naval Univ Engn Naval Inst Underwater Acoust Technol Wuhan Peoples R China Leador Space Informat Technol Co Ltd Wuhan Peoples R China

ISBN: (纸本)9781510605039;9781510605046

With the increase of the ratio between signal bandwidth and carrier frequency in the synthetic aperture sonar system, most of conventional imaging algorithms cannot be used for their narrow band approximation inherently. This paper analyzes the determining factors in designing an effective chirp scaling (CS)-based algorithms for focusing the wideband and wide swath synthetic aperture data. Based on the analysis, it is a great potential in designing an effective CS-based wideband and wide swath algorithm for taking into account the higher- order terms with respect to the range baseband frequency in the approximation of the 2-D spectrum and taking into account the higher-order range-variant terms in the approximation of the equivalent chirp rate. The results of simulation show the effectiveness of the theory analysis.

关键词： imaging algorithm synthetic aperture wideband wide swath chirp scaling

来源：评论

学校读者我要写书评

暂无评论

An Efficient TOPS imaging algorithm Based on Spectral Analysis

An Efficient TOPS Imaging Algorithm Based on Spectral Analys...

引用

IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC)

作者： Wang, XiaoBei Yin, Peng Ding, ZeGang Yan, XueMei Beijing Inst Technol Sch Informat & Elect Radar Res Lab Beijing Key Lab Embedded Real Time Informat Proc Beijing 100081 Peoples R China CAST Beijing Inst Spacecraft Syst Engn Beijing 100094 Peoples R China

ISBN: (纸本)9781509027088

The Terrain Observation by Progressive Scans (TOPS) mode solves the problems existing in the conventional ScanSAR mode by steering the antenna along the azimuth direction. However, the antenna steering introduces a serious azimuth signal aliasing both in time-domain and frequency-domain, thus traditional imaging algorithms are not available for the TOPS mode. In order to solve the azimuth signal aliasing, an efficient TOPS imaging algorithm based on spectral analysis (SPECAN) is presented in this paper, which is improved by subapertures division in the azimuth processing part. Only few FFTs and complex multiplications are used in the whole imaging processing, thus the algorithm has a high efficiency. What's more, in the final focused image, different ranges have the same azimuth interval and the azimuth image resolution is alterable according to the application requirements. Finally, some simulations are conducted to verify the validity of the proposed method.

关键词： TOPS efficient imaging algorithm SPECAN subaperture division

来源：评论

学校读者我要写书评

暂无评论

An Improved Back Projection algorithm for Terahertz imaging

引用

IEEE SENSORS JOURNAL 2025年第10期25卷 17761-17768页

作者： Wang, Guanwen Qi, Feng Shenyang Univ Technol Sch Informat Sci & Engn Shenyang 110870 Peoples R China Key Lab Liaoning Prov Terahertz Imaging & Sensing Shenyang 110169 Peoples R China Chinese Acad Sci Key Lab Optoelect Informat Proc Shenyang 110169 Peoples R China

In this article, an analytical algorithm based on inverse matrix solution is proposed to perform imaging based on near-field terahertz (THz) scan data. The computational framework of conventional back projection algorithms (BPAs) comprises four principal stages. The initial procedure discretizes the target region via structured mesh partitioning. This was followed by the subsequent computation of wave propagation time delays for each discrete pixel element. Phase correction operations were then performed to compensate for waveform distortions. Ultimately, image reconstruction was achieved through coherent integral of back propagated signals. In contrast to the conventional BPA, this proposed approach reconstructed the signal propagation model. It achieves this by transforming the back projection process into an inverse problem solution, which is then used to solve the forward propagation of the signal. It can solve the inverse problem more accurately by obtaining the actual reflectivity of each pixel of the target. The computed results are closer to the electromagnetic (EM) field distribution of the real scene, reducing the error caused by energy in the subaperture signal unrelated to the imaging region compared to BPA. The radial resolution has, moreover, been improved by over 30%. Those absorbers, which are generally invisible in radar imaging due to very weak reflections, can be visualized beyond classical BPA. In the imaging process of complex targets, enhanced precision in EM calculations facilitates more comprehensive reconstructions. The algorithm can be used for elaborate environment imaging and sensing in the future.

关键词： imaging Radar imaging Apertures Mathematical models Antenna measurements Image reconstruction Data acquisition Terahertz wave imaging Intelligent sensors Frequency-domain analysis Complex target rebuilt imaging algorithm inverse matrix solution terahertz (THz) imaging

来源：评论

学校读者我要写书评

暂无评论

Accurate Microwave Near-Field imaging of Multiple High-Order Scattering Objects Using Iterative Tracing algorithm

引用

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2025年 74卷

作者： Yang, Junhui Zhuge, Xiaodong Qiao, Hui Xing, Baige Miao, Jungang Beihang Univ Sch Elect & Informat Engn Beijing 100191 Peoples R China

Conventional microwave imaging algorithms excel in scenarios involving only single scattering, but often encounter imaging artifacts when processing higher order scattering. Previous studies have demonstrated the possibility for accurate imaging of higher order scattering fields in typical planar concave objects. However, these algorithms still encounter difficulties when applied to curved objects with unfixed reflection planes. To solve this problem, we propose an iterative tracing algorithm to establish the forward propagation model of the curved objects. Then an iterative reconstruction method is introduced to automatically separate the scattered fields of each order and accurately reconstruct the target by compensating for both amplitude and phase using the forward model. The illumination areas on the target for different high-order scattering components are further quantitatively analyzed using the proposed forward model. We compare our proposed method with the state-of-the-art imaging algorithms in terms of computational complexity and imaging accuracy. Numerical simulations and experiments are performed to validate the effectiveness of our algorithm.

关键词： imaging Scattering Reflection Mirrors Geometry Microwave imaging Lighting Iterative algorithms Image reconstruction Accuracy Coupling targets high-order scattering image artifacts image reconstruction imaging algorithm microwave imaging multiple scattering propagation model

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：