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Ground moving target detection and location based on SAR images for distributed spaceborne SAR

science in China(Series F) 2005年第5期48卷 632-646页

作者： LI Zhenfang BAO Zheng YANG Fengfeng Key Laboratory for Radar Signal Processing Xidian University Xran 710071 China National University of Defence Technology Changsha 4100731 China

This paper investigates data processing approaches to detect and locate ground moving targets using distributed spaceborne SAR systems with long cross-track baselines. In particular, it investigates the performance of ground moving target detection for two typical satellite formations： Cartwheel and Pendulum. An approach based on SAR images and a space-time adaptive processing （STAP） algorithm is proposed in order to overcome the effects of the ground terrain on the clutter suppression. The key idea of the approach is firstly to reduce the clutter degrees of freedom greatly by using conventional SAR imaging processing. Then the ground terrain clutter within each SAR pixel can be effectively cancelled by using the very limited spatial degrees of freedom. Finally, constant-false-alarm-rate （CFAR） techniques can be used to detect the remaining target SAR pixels after clutter cancellation. An approach to relocate the detected targets is also proposed, which is based on the estimation of the Doppler spectrum shifts of ground moving targets relative to the clutter Doppler spectrum. The proposed approaches in this paper have the advantages of simplicity and high efficiency.

关键词： formation-flying satellites ground moving target indication spaceborne synthetic apertureradar （spaceborne SAR） space-time adaptive processing （STAP） cartwheel pendulum.

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Roll-pitch-yaw autopilot design for nonlinear time-varying missile using partial state observer based global fast terminal sliding mode control

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Chinese Journal of Aeronautics 2016年第5期29卷 1302-1312页

作者： Ahmed Awad Wang Haoping Sino-French International Joint Laboratory of Automatic Control and Signal Processing (LaFCAS) School of AutomationNanjing University of Science & Technology

The acceleration autopilot design for skid-to-turn （STT） missile faces a great challenge owing to coupling effect among planes, variation of missile velocity and its parameters, inexistence of a complete state vector, and nonlinear aerodynamics. Moreover, the autopilot should be designed for the entire flight envelope where fast variations exist. In this paper, a design of integrated roll-pitch-yaw autopilot based on global fast terminal sliding mode control （GFTSMC） with a partial state nonlinear observer （PSNLO） for STT nonlinear time-varying missile model, is employed to address these issues. GFTSMC with a novel sliding surface is proposed to nullify the integral error and the singularity problem without application of the sign function. The proposed autopilot consisting of two-loop structure, controls STT maneuver and stabilizes the rolling with a PSNLO in order to estimate the immeasurable states as an output while its inputs are missile measurable states and control signals. The missile model considers the velocity variation, gravity effect and parameters＇ variation. Furthermore, the environmental conditions＇ dynamics are mod- eled. PSNLO stability and the closed loop system stability are studied. Finally, numerical simulation is established to evaluate the proposed autopilot performance and to compare it with existing approaches in the literature.

关键词： Flight control system Global fast terminal slidingmode control Integrated autopilot Nonlinear state observer Skid-to-turn missile

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Application of Adaptive Filters to Active Noise Control

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中国电子杂志（英文版） 2001年第4期10卷 548-551页

作者： PEI Bingnan LI Chuanguang Key Laboratory for Radar Signal Processing Xidian University Xi'an 710071 China Department of Automatic Control Beijing Institute of Technology Beijing 100081 China

A modified LMS algorithm for noise-control is suggested after a mathematical model ofsound-cancellation is established, on the basis of thesound wave interference principle and the physicalmodel of progressive waves in a duct. Its applicationin controlling noise with the frequency range from 100to 800 Hz can be implemented by using the adaptivedigital signal processing technique. The experimentson a pink noise, a broadband noise and a noise takenfrom a tank were made, which show that there existsan attenuation of 11 dB at the frequency of 500 Hzor so, and that the proposed adaptive noise controltechnique is very effective and valid.

关键词： Adaptive digital filters Active noisecontrol Digital signal processor Environmental engi-neering.

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An Accurate Near-Field Distance Estimation Differential Algorithm

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Chinese Journal of Electronics 2022年第5期31卷 851-859页

作者： ZHAO Yan TAO Haihong CHANG Xin National Key Laboratory of Radar Signal Processing Xidian Univercity The 54th Research Institute China Electronics Technology Group Corporation School of Electronic Engineering Xidian University

The triangular geometry is the basis of near field array accurate distance estimation *** Fisher expression of traditional distance estimation is derived by utilizing the Taylor series. To improve convergence rate and estimation accuracy, a novel iterative distance estimation algorithm is proposed with differential equations based on the triangular geometry. Firstly, its convergence performance is analysed in detail. Secondly,the selection of the initial value and the number of iterations are respectively studied. Thirdly, compared with the traditional estimation algorithms by utilizing the Fisher approximation, the proposed algorithm has a higher convergence rate and estimation accuracy. Moreover, its pseudocode is presented. Finally, the experiment results and performance analysis are provided to verify the effectiveness of the proposed algorithm.

关键词： iterative methods iterative distance estimation convergence performance triangular geometry Fisher expression approximation theory convergence near-field distance estimation Fisher approximation Taylor series differential equations estimation theory

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A spectrum-enhanced attention model for semantic segmentation of remote sensing images

A spectrum-enhanced attention model for semantic segmentatio...

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International Conference on Acoustics, Speech, and signal processing (ICASSP)

作者： Xin Li Feng Xu Feifei Tao Yao Tong Xin Lyu Jianyi Zhong André Kaup College of Computer Science and Software Engineering Hohai University Nanjing China Key Laboratory of Water Big Data Technology of Ministry of Water Resources Hohai University Nanjing China School of Computer Engineering Jiangsu Ocean University Lianyungang China School of Artificial Intelligence and Information Technology Nanjing University of Chinese Medicine Nanjing China Chair of Multimedia Communications and Signal Processing Friedrich-Alexander University Erlangen-Nuremberg Erlangen Germany

ISBN: (数字)9798350368741

ISBN: (纸本)9798350368758

Semantic segmentation of remote sensing images (RSIs) is essential for applications such as environmental monitoring, urban planning, and disaster management. Convolutional Neural Networks (CNNs) and their variants struggle to capture comprehensive spectral context for learning discriminative representations. In this paper, we propose a Spectrum-Enhanced Network (SPENet) that leverages the Frequency Transformer Block (FTB) to capture rich spectral context. FTB integrates Spectrum-Enhanced Attention (SEA) with Multi-Head Frequency Self-Attention (MH-FSA), incorporating more informative contextual cues. Specifically, SEA aggregates spectral statistics through covariance matrix normalization before applying channel-wise attention. By projecting feature maps onto the frequency domain, MH-FSA provides the network with a broader context, extending beyond the low-frequency focus of standard self-attention mechanisms. Extensive experiments on the ISPRS Potsdam and LoveDA datasets show that SPENet significantly outperforms state-of-the-art methods. Besides, the proposed SEA module notably rises average F1-score/overall accuracy/mean insert over union wiht more than 2.5/2.6%/2.3%, as demonstrated by ablation study.

关键词： Semantic segmentation Frequency-domain analysis Urban planning Semantics Speech enhancement signal processing Transformers Sensors Remote sensing Standards

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High-Precision DOA Estimation Method Based on Synthetic Aperture Technique

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Journal of Beijing Institute of technology 2024年第2期33卷 111-118页

作者： Yongjia Dou Guangcai Sun Yuqi Wang Mengdao Xing National Key Laboratory of Radar Signal Processing Xidian UniversityXi’an 710071China School of Communication and Information Engineering Xi’an University of Science and TechnologyXi’an 710054China

The existing direction-of-arrival(DOA)estimation methods only utilize the current received signals,which are susceptible to *** this paper,a method for DOA estimation based on a motion platform is proposed to achieve high-precision DOA estimation by utilizing past and present *** concept of synthetic aperture is introduced to construct a linear DOA estima-tion model.A DOA fine-tuning method based on the linear model is proposed to eliminate the lin-ear DOA variation,achieving a non-coherent accumulation of DOA ***,the baseband modulation and the phase modulation caused by the range history are compensated to achieve the coherent accumulation of all the DOA *** results show that the proposed method can significantly improve the DOA estimated accuracy at low signal-to-noise ratios(SNR).

关键词： synthetic aperture direction-of-arrival(DOA)estimation coherent accumulation

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Generalized Tensor-Aided Channel Estimation for Hardware Impaired Device Identification

arXiv

引用

arXiv 2025年

作者： Wu, Qi Sui, Zeping Ngo, Hien Quoc Wan, Qun Matthaiou, Michail School of Information and Communication Engineering University of Electronic Science and Technology of China Chengdu611731 China National Key Laboratory on Blind Signal Processing Chengdu610041 China Queen’s University Belfast BelfastBT3 9DT United Kingdom Department of Electronic Engineering Kyung Hee University Gyeonggi-do Yongin-si17104 Korea Republic of

In this paper, we investigate the joint generalized channel estimation and device identification problem in Internet of Things (IoT) networks under multipath propagation. To fully utilize the received signal, we decompose the generalized channel into three components: transmitter hardware characteristics, path gains, and angles of arrival. By modeling the received signals as parallel factor (PARAFAC) tensors, we develop alternating least squares (ALS)-based algorithms to simultaneously estimate the generalized channels and identify the transmitters. Simulation results show that the proposed scheme outperforms both Khatri-Rao Factorization (KRF) and the conventional least squares (LS) method in terms of channel estimation accuracy and achieves performance close to the derived Cramér–Rao lower bound. © 2025, CC BY.

关键词： Tensors

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Generalized Tensor-Aided Channel Estimation for Hardware Impaired Device Identification

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IEEE Transactions on Vehicular technology 2025年

作者： Wu, Qi Sui, Zeping Ngo, Hien Quoc Wan, Qun Matthaiou, Michail School of Information and Communication Engineering University of Electronic Science and Technology of China Chengdu611731 China National Key Laboratory on Blind Signal Processing Chengdu610041 China Queen’s University Belfast BelfastBT3 9DT United Kingdom School of Computer Science and Electronics Engineering University of Essex ColchesterCO4 3SQ United Kingdom Department of Electronic Engineering Kyung Hee University Gyeonggi-do Yongin-si17104 Korea Republic of

关键词： Tensors

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Practical frequency-hopping MIMO joint radar communications:Design and experiment

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Digital Communications and Networks 2024年第6期10卷 1904-1914页

作者： Jiangtao Liu Kai Wu Tao Su J.Andrew Zhang National Key Laboratory of Radar Signal Processing Xidian UniversityXi'anShanxi 710071China Global Big Data Technologies Centre University of Technology SydneyNSW 2007Australia

Joint radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both ***-Hopping(FH)MIMO radar is a popular candidate for JRC because the achieved communication symbol rate can greatly exceed the radar pulse repetition ***,practical transceiver imperfections can cause many existing theoretical designs to *** this work,we reveal for the first time the non-trivial impact of hardware imperfections on FH-MIMO JRC and model the impact *** also design new waveforms and correspondingly develop a low-complexity algorithm to jointly estimate the hardware imperfections of unsynchronized *** addition,using low-cost software-defined radios and Commercial Off-The-Shelf(COTS)products,we build the first FH-MIMO JRC experimental platform with simultaneous over-the-air radar and communication *** by simulation and experimental results,the proposed designs achieve high performance for both radar and communications.

关键词： Joint radar and communications Frequency-hopping MIMO radar Sampling timing offset Carrier frequency offset Front-end errors Software-defined radio Commercial off-the-shelf

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Design of a Crooked-Wire Antenna by Differential Evolution and 3D Printing

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International Journal of Cognitive Informatics and Natural Intelligence 2021年第4期15卷 1-16页

作者： Zhao, Fei Xu, Qinghui Zeng, Sanyou Science and Technology on Blind Signal Processing Laboratory United States China University of Geosciences China

Antenna design often requires dealing with multiple constraints in the requirements, and the designs can be modeled as constrained optimization problems (COPs). However, the constraints are usually very strange, and then the feasible solutions are hard to find. At the same time, the robustness for antenna design is an important consideration as well. To solve the above issues, the combination of differential evolution algorithm (DE) and 3D-printing technique is presented to design a new crookedwire antenna. In the design process, DE is adopted to handle the constraints since DE is simple and efficient in finding feasible solutions. The objective of the modeled COP, which is the sum of variance of the gain, axial ratio, and VSWR over the frequency band, is used to enhance the robustness of the antenna and widen the frequency band without additional computational cost. The precision of fabricating the antenna is ensured by using 3D-printing. The design of the NASA LADEE satellite antenna is chosen as an example to verify the method of this paper. Experimental results show that the performance of the evolved antenna meets the design requirements. © 2021 IGI Global. All rights reserved.

关键词： Satellite antennas

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