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Signal, information and Data processing (ICSIDP), IEEE International Conference on

作者： HuiXing Li ZiXin Gao BingYi Li Yi Zhuang Xie Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology Beijing China Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing China Beijing Institute of Radio Measurement Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

Aiming at the problem of insufficient memory in the real-time processing of SAR imaging on embedded TX2, this paper studies a design optimization scheme of fixed-point imaging algorithm on TX2. In order to ensure the accuracy, this paper only performs fixed-point processing on the FFT. According to the characteristics of the algorithm, the memory multiplexing method is adopted to effectively reduce the occupation of the work area buffer. A large number of registers are used to improve computing performance. The results show that the fixed-point FFT processing scheme can achieve a hundred times faster than the Intel Xeon CPU, and the memory footprint is less.

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An improved RUDP for data transmission in embedded real-time system

An improved RUDP for data transmission in embedded real-time...

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Signal, information and Data processing (ICSIDP), IEEE International Conference on

作者： Yingying Chen Shanqing HU Xingming LI Ce Wang Zhe Chen Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of technology Beijing China Beijing Racobit Electronic Information Technology Co. Ltd Beijing China Academy of Broadcasting Science Internet Technology Institute Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

At present, the Ethernet has been widely used for data transmission in embedded real-time systems, including TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). However, as embedded real-time systems continue to increase the requirements of transmission speed and reliability, TCP and UDP have not been able to meet the requirements. TCP is a stream-based, connection-oriented communication protocol, so the reliability of TCP is good. But its design is complicated, it occupies a lot of system resources, and the transmission speed of TCP is low. In contrast, UDP is non-connection-oriented protocol, so it is unreliable communication protocol. Both of them limit the Ethernet applying in embedded real-time systems. In order to meet the requirements of real-time, reliability and algorithm simplicity of embedded systems, this paper proposed an improved Reliable User Datagram Protocol (RUDP), which offers a solution to satisfy these requirements. It is valid on the real demonstration that the proposed method can offer a higher speed than TCP without package loss.

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A modified imaging interval selection method based on joint time-frequency analysis for ship ISAR imaging 12

A modified imaging interval selection method based on joint ...

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12th European Conference on Synthetic Aperture Radar, EUSAR 2018

作者： Li, Gen Zhang, Tianyi Li, Yong Ding, Zegang Ke, Meng Radar Research Lab School of Information and Electronics Beijing Institute of Technology China Beijing Key Laboratory of Embedded Real-Time Information Processing Technology Radar Research Lab School of Information and Electronics Beijing Institute of Technology China

ISBN: (纸本)9783800746361

Selecting proper imaging intervals where the ship rotation vector is constant is a very simple method to obtain high-quality ship inverse synthetic aperture radar (ISAR) images. However, existing imaging interval selection methods are usually based on traversal or iteration, which means that they are time-consuming and complex. Thus, to realize imaging interval selection simply and effectively, a modified imaging interval selection method based on joint time-frequency analysis (JTFA) is proposed in paper. Compared with the traditional range-Doppler algorithm (RDA), the proposed method just has one added step of JTFA. real data processing results validate the effectiveness and superiority of the proposed method. © VDE VERLAG GMBH Â Berlin Â Offenbach.

关键词： Ships

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The Verification System of Sliding Spotlight Mode SAR Imaging based on SoPC

The Verification System of Sliding Spotlight Mode SAR Imagin...

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Signal, information and Data processing (ICSIDP), IEEE International Conference on

作者： Shankang Hu Yizhuang Xie Jie Lian Bingyi Li Beijing Institute of Remote Sensing Equipmentt BeiJing China Beijing Key Laboratory of Embedded Real-Time Information Processing Technology Beijing Institute of Technology Beijing China Beijing Institute of Radio Metrology and Measurement Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

Aiming at the application background of sliding spotlight mode Synthetic Aperture Radar (SAR) imaging processing, this paper builds a System-on-a-Programmable-Chip-based (SoPC-based) sliding spotlight mode SAR imaging verification system, which uses software and hardware collaborative design method to complete algorithm-to-hardware mapping and can quickly and truly perform in FPGA or ASIC. Finally, we analyzed the implementation of the imaging prototype system and the imaging results. For the generation of correlation factors, this paper hierarchically decomposes the factor generation operation to realize the time division multiplexing of the operation unit, in order to reduce resource consumption. At the same time, a variable point Fast Fourier Transformation (FFT) processor based on a variable radix-2 3 multiplexing butterfly unit is designed and implemented. Combining these two parts with other modules enables the entire sliding spotlight mode imaging process. On the basis of keeping the error of the result small, the overall resource consumption is greatly reduced. The 1024~32768 point FFT is implemented by the top-level configurable method, and the operation delay is reduced by more than 20% compared with the Xilinx FFT IP core. The final imaging time is reduced to seconds, and the imaging results meet the requirements. Subsequent compatibility design for other SAR imaging modes also can be achieved.

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Multi-dimensional spectral super-resolution with prior knowledge via frequency-selective Vandermonde decomposition and ADMM

arXiv

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arXiv 2019年

作者： Li, Yinchuan Wang, Xiaodong Ding, Zegang School of Information and Electronics Beijing Institute of Technology Beijing100081 China Electrical Engineering Department Columbia University New YorkNY10027 United States Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing100081 China

This paper is concerned with estimation of multiple frequencies from incomplete and/or noisy samples based on a low-CP-rank tensor data model where each CP vector is an array response vector of one frequency. Suppose that it is known a priori that the frequencies lie in some given intervals, we develop efficient super-resolution estimators by exploiting such prior knowledge based on frequency-selective (FS) atomic norm minimization. We study the MD Vandermonde decomposition of block Toeplitz matrices in which the frequencies are restricted to lie in given intervals. We then propose to solve the FS atomic norm minimization problems for the low-rank spectral tensor recovery by converting them into semidefinite programs based on the MD Vandermonde decomposition. We also develop fast solvers for solving these semidefinite programs via the alternating direction method of multipliers (ADMM), where each iteration involves a number of refinement steps to utilize the prior knowledge. Extensive simulation results are presented to illustrate the high performance of the proposed methods. Copyright © 2019, The Authors. All rights reserved.

关键词： Optical resolving power

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Multi-target position and velocity estimation using OFDM communication signals

arXiv

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arXiv 2019年

作者： Li, Yinchuan Wang, Xiaodong Ding, Zegang School of Information and Electronics Beijing Institute of Technology Beijing100081 China Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing100081 China Electrical Engineering Department Columbia University New YorkNY10027 United States

In this paper, we consider a passive radar system that estimates the positions and velocities of multiple moving targets by using OFDM signals transmitted by a totally un-coordinated and unsynchronizated illuminator and multiple receivers. It is assumed that data demodulation is performed separately based on the direct-path signal, and the error-prone estimated data symbols are made available to the passive radar receivers, which estimate the positions and velocities of the targets in two stages. First, we formulate a problem of joint estimation of the delay-Doppler of reflectors and the demodulation errors, by exploiting two types of sparsities of the system, namely, the numbers of reflectors (i.e., targets and clutters) and demodulation errors are both small. This problem is non-convex and a conjugate gradient descent method is proposed to solve it. Then in the second stage we determine the positions and velocities of targets based on the estimated delay-Doppler in the first stage. And two methods are proposed: the first is based on numerically solving a set of nonlinear equations, while the second is based on the back propagation neural network, which is more efficient. The performance of the proposed passive OFDM radar receiver algorithm is evaluated through extensive simulations. Copyright © 2019, The Authors. All rights reserved.

关键词： Radar receivers

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OPTICAL REMOTE SENSING WATER-LAND SEGMENTATION REPRESENTATION BASED ON PROPOSED SNS-CNN NETWORK

OPTICAL REMOTE SENSING WATER-LAND SEGMENTATION REPRESENTATIO...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Shan Dong Long Pang Yin Zhuang Wenchao Liu Zhanxin Yang Teng Long Engineering Center of Digital Audio and Video Communication University of China Beijing China School of Electronic Engineering and Computer Science Peking University Beijing China Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology Beijing China

For water resource analysis applications, due to very high resolution and large observation scope, optical remote sensing images can present more visible object characters. Water-land segmentation from optical remote sensing images is wildly used and becomes a hot research topic. However, since large scale complex background scenes include many interferences, the water-land segmentation from optical remote sensing images becomes a challenge task. Aim to achieve better water area feature description from complex land cover background, we apply a sub-neighbor system convolutional neural network (SNS-CNN) to the water-land segmentation in harbor scene areas. First, on the basis of the U-net structure, an optimized up-sampling process is proposed to enhance water area feature expression. Second, a novel sub-neighbor system constraint of each predicted pixel point is leaded into the loss function to make the model producing water mask more coherent. Furthermore, experiments on our collected variety of optical remote sensing images demonstrate that this paper proposed water-land segmentation method can produce better performance than state of the art methods.

关键词： Image segmentation Convolution Remote sensing Optical imaging Optical sensors Feature extraction Convolutional neural networks

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Image representation of GEO SAR time-variant scene 12

Image representation of GEO SAR time-variant scene

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12th European Conference on Synthetic Aperture Radar, EUSAR 2018

作者： Zhu, Yu Ke, Meng Zhang, Tianyi Li, Gen Ding, Zegang Beijing Institute of Spacecraft System Engineering CAST China Radar Research Lab School of Information and Electronics Beijing Institute of Technology China Beijing Key Laboratory of Embedded Real-Time Information Processing Technology Radar Research Lab School of Information and Electronics Beijing Institute of Technology China

ISBN: (纸本)9783800746361

Geosynchronous synthetic aperture radar (GEO SAR) is characterized by large coverage and short revisit time, and has great potentials for environment monitoring. The GEO SAR image of variant scene is obviously different from the traditional SAR image, because of the extremely long illumination time, which greatly increases the difficulty of SAR image interpolation. To further understand the GEO SAR images of the time-variant scenes, the geometry models and backscattering models of time-variant grassland and water surface are established. Furthermore, the GEO SAR images of them are obtained by simulation, which is benefit for the understanding of GEO SAR images. © VDE VERLAG GMBH Â Berlin Â Offenbach.

关键词： Synthetic aperture radar

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Beam scan mode analysis and design for geosynchronous SAR

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Science China(information Sciences) 2017年第6期60卷 72-84页

作者： Wei YIN Zegang DING Xiaojun LU Yu ZHU Beijing Key Laboratory of Embedded Real-time Information Processing Technology School of Information and Electronics Beijing Institute of Technology Beijing Institute of Spacecraft System Engineering Chinese Academy of Space Technology

The beam velocity of geosynchronous synthetic aperture radar(GEO SAR) varies seriously with the orbital position and the scene position, which leads to a significant variation of the scene length and the azimuth resolution in the stripmap(SM) mode. To obtain uniform scene length and azimuth resolution, beam scan modes can be utilized in GEO SAR, such as the sliding spotlight(SLL) mode and the terrain observation by progressive scans(TOPS) mode. However, the conventional design method of the beam scan mode is based on the straight line model(SLM), which does not consider the effects of the curved satellite track and the spherical earth surface. To solve this problem, a curvature circle model(CCM) is proposed considering the actual satellite-earth relationship. By using the CCM, the beam velocity after the beam scan is derived. The scene length and the azimuth resolution are analyzed. The SLL mode and the TOPS mode are recommended for GEO SAR. After that, a design method of the beam scan mode is proposed based on the CMM. The performance of the proposed method is verified by computer simulations.

关键词： GEO SAR beam scan mode design azimuth resolution scene length

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CONSTRAINED NONNEGATIVE MATRIX FACTORIZATION FOR ROBUST HYPERSPECTRAL UNMIXING

CONSTRAINED NONNEGATIVE MATRIX FACTORIZATION FOR ROBUST HYPE...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Fan Feng Chenwei Deng Wenzheng Wang Jiahui Dai Zhenzhen Li Baojun Zhao Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology China

Hyperspectral unmixng (HU) is an essential step for hyperspectral image (HSI) analysis. In real HSI, there often are abnormal fluctuations existing in specific bands, which can be described as sparse noise. This type of corruption will seriously disrupt the hyperspectral image quality, causing extra difficulties during unmixing process. However, the influence of sparse noise is often ignored by existing unmixing methods, which leads to the reduction of robustness and accuracy for HU tasks. Therefore, we propose a new unmixing model which takes noise corruption into consideration. By designing and imposing constraints considering the sparsity of noise, properties of endmember and abundance on nonnegative matrix factorization (NMF), the proposed method can resist the sparse noise and achieve more robust and accurate unmixing results. Adequate experiments have been conducted on both synthetic and real hyperspectral data. And the results confirm the superiority of proposed method compared to state-of-the-art methods.

关键词： Hyperspectral imaging Sparse matrices Robustness Task analysis Clustering algorithms

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