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2016 6th International Conference on Mechatronics,Materials,Biotechnology and Environment(ICMMBE 2016)

作者： Tao Yan Shanqing Hu Xingming Li Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology Tsinghua University

With the rapid development of radarsignal processing systems, a great demand of high-speed communication is required. JESD204 B interface has become an outstanding solution for ADC-related data transmission, and has been widely applied. However, the synchronization of multiply JESD204B-based ADCs has been a challenge because of the special feature such as deterministic latency. In this paper, we design a data acquisition system integrated two JESD204B-based ADCs, and proposed a general and flexible synchronization method based on FPGA, by using and controlling deterministic latency. As is validated by the practical measurements,the method can maintainaphase difference between the two 2.5Gbps ADCsfrom17 ps to 22 psstably, forthe signals of frequencies less than 1.8GHz.

关键词： JESD204B deterministic latency synchronization Radar system

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Dem-assisted back-projection algorithm in high resolution geosynchronous SAR imaging

Dem-assisted back-projection algorithm in high resolution ge...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： YuanHao Li XiChao Dong Kai Cui Cheng Hu DongYang Ao Teng Long School of Information and Electronics Beijing Institute of Technology Beijing Beijing Key Laboratory of Embedded Real-time information Processing Technology Beijing

Since geosynchronous synthetic aperture radar (GEO SAR) has curved trajectories, back-projection algorithm (BPA) greatly fits for its imaging. However, for a scene with height variation, the reference range based on the fixed-height imaging grid under curved trajectories is inaccurate in azimuth back-projection. Resultantly, the GEO SAR image quality will be obviously deteriorated in high resolution imaging. To address the issue, this paper proposed the digital elevation model (DEM)-assisted BPA to realize the accurate high resolution GEO SAR imaging for the scene with height variation. DEM information is utilized to construct the imaging grid in the new method for generating the accurate reference range. Simulation results validate that the proposed method achieves good imaging performance for the scene with height variation.

关键词： Imaging Azimuth Image resolution Synthetic aperture radar Trajectory Radar polarimetry Orbits

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A novel TOA estimation method for unknown signal based on intra-pulse correlation accumulation

A novel TOA estimation method for unknown signal based on in...

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

作者： Jiacen Xu Zhongyi Wang Quanhua Liu Lixiang Ren Beijing Key Laboratory of Embedded Real-time Information Processing Technology School of Information and Electronics Beijing Institute of Technology Beijing China

ISBN: (纸本)9781509027095

This paper presents a novel low complexity time-of arrival (TOA) estimation method for unknown intra-pulse modulated signal under low SNR condition. The received signal is firstly pre-processed by delayed conjugate multiplication to reduce the intra-pulse modulation and get a rough range of the signal. Then a novel intra-pulse correlation accumulation method is applied to achieve a precise estimation of rising and falling edge. Simulations are conducted to show the feasibility of the method and evaluate the performance of estimation. Compared with existing methods, this novel method can achieve a better estimation result.

关键词： Estimation Signal to noise ratio Correlation time of arrival estimation Smoothing methods Frequency modulation

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MICRO-DOPPLER EXTRACTION FROM ISAR IMAGE

MICRO-DOPPLER EXTRACTION FROM ISAR IMAGE

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IEEE International Conference on Acoustics, Speech and Signal processing

作者： Feng Li Jun Cao Lixiang Ren Teng Long Beijing Key Laboratory of Embedded Real-Time Information Processing Technology School of Information and Electronics Beijing Institute of Technology Beijing China

ISBN: (纸本)9781479999897

The micro-Doppler is an effective tool for target recognition. It is hard to detect micro-Doppler induced by vibration for its small value. In our system, phase-modulated stepped-frequency waveform is used. The method of matching pursuit (MP) is introduced to compensate translation. Translation trajectory is approximated by Chebyshev polynomial to improve approximation accuracy under low signal-to-noise ratio. The parameters in the polynomial are estimated by MP. To improve the performance of MP, simulated annealing is used. The operation of translation parameters estimation is performed in frequency domain before pulse compression. After translation compensation and pulse compression, Doppler component induced by rotation is mitigated by phase fitting. After compensation of translation and rotation, micro-Doppler is extracted from the result of motion compensation based on vibration model. Simulation and experiment data are used to testify our method.

关键词： Chebyshev polynomial matching pursuit micro-Doppler simulated annealing stepped-frequency waveform

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GNSS-based BiSAR imaging using modified range migration algorithm

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Science China(information Sciences) 2015年第8期58卷 144-156页

作者： ZENG Tao LIU FeiFeng ANTONIOU Michail CHERNIAKOV Mikhail Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology School of Electronic Electrical and Systems Engineering University of Birmingham

This paper proposed a new focusing approach for the bistatic SAR systems with a GNSS(Global Navigation Satellite System) satellite as the transmitter. Because of the long integration time the inherited curvature of the transmitter’s trajectory was adopted and the spatial variance of the equivalent velocity was derived under the principal of equivalent slant range model in the system signal model. The proposed focusing approach consists of two-step processing. Firstly, the general Doppler phase from constant velocity of the echo data is focused by modified Stolt mapping. Secondly, the residual nonlinear Doppler phase due to velocity variation is compensated by means of block-processing-based adaptive phase compensation to achieve large scene focusing. The simulation and experimental results validate the proposed algorithm in GNSS-based Bi SAR systems.

关键词： GNSS-based Bi SAR equivalent slant range model curvature of trajectory two-step processing modified Stolt mapping

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DEM generation using bistatic interferometry:high-coherence pixel selection and residual reference phase compensation

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Science China(information Sciences) 2015年第6期58卷 25-38页

作者： ZENG Tao ZHU Mao HU Cheng TIAN WeiMing ANTONIOU Michail Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology School of Electronic Electrical and Systems Engineering University of Birmingham

The bistatic spaceborne/stationary In SAR configuration could be applied to generate digital elevation model(DEM). However, two factors limit the DEM precision improvement. On one hand, due to the effects of the illuminator’s sidelobe and the high objects’ shadow, the pixels in the corresponding area might be polluted by the noise. On the other hand, owing to the presence of deviation(between the real value and the nominal value of the master/slave antenna positions), after utilizing the nominal value to compensate for the reference phase, the residual reference phase would remain. In order to solve the problems, we proposed a new bistatic DEM generation algorithm. Firstly, we applied the coherence-phase joint analysis method to select high-coherence points. Secondly, we deduced the transforming relationship from the deviation to the residual reference phase, and then compensated for the residual reference phase. In the experiment, the Yao Gan-3(an L-band spaceborne SAR) was selected as the transmitter and the two stationary receivers were mounted on the top of a tall building. The algorithm recommended in this paper was applied to process the measured bistatic data. The analysis of the results demonstrated that the elevation error of the generated DEM for some targets had been limited to the level of 1–2 m.

关键词： bistatic In SAR high coherence pixel DEM SAR bistatic SAR

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SAR geometric correction algorithm improvement on multi-core C6678 DSPs

SAR geometric correction algorithm improvement on multi-core...

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

作者： Mengyu Lu Jinghua Wang Jin Ye Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing China Department of Overall Design China Academy of Space Technology Beijing China

This paper achieves the SAR geometric correction algorithm and makes improvements based on multi-core C6678 DSPs. To solve the insufficient real-time problem, this paper improves the geometric correction, and designs process software that can meet the real-time requirements, from the process flow, process algorithm and storage process aspects. This paper describes the multiple DPSs parallel process scheme and multi-core mapping tasks, and makes a comparison of the time-consuming before optimization and after. And after the optimization, the geometric correction's efficiency is two times of the original. After verification, the parallel process software designed in this paper can meet the real-time requirements of the project, and also has good stability.

关键词： Digital signal processing Algorithm design and analysis Azimuth real-time systems Quantization (signal) Synthetic aperture radar Optimization

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Corrections to “Performance Analysis of L-Band Geosynchronous SAR Imaging in the Presence of Ionospheric Scintillation” [Jan 17 159-172]

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IEEE Transactions on Geoscience and Remote Sensing 2017年第1期55卷 615-615页

作者： Cheng Hu Yuanhao Li Xichao Dong Rui Wang Dongyang Ao Beijing Key Laboratory of Embedded Real-Time Information Processing Technology Beijing China School of Information and Electronics Beijing Institute of Technology Beijing China Department of Electronic Engineering Tsinghua University Beijing China

In the above paper [1] there are errors in several places: 1) the first lines of text at the top left of page 3; 2) equations (2) , (11), (12), (13) , and (15) ; and 3) Fig. 3 . Their correct forms are presented... 详细信息

关键词： L-band Synthetic aperture radar Ionosphere Low earth orbit satellites Image analysis

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A novel threshold template algorithm for ship detection in high-resolution SAR images

A novel threshold template algorithm for ship detection in h...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Chonglei Wang Funkun Bi Liang Chen Jing Chen Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology Beijing China School of Electronic Information Engineering North China University of Technology Beijing China

A new threshold template algorithm is presented in this paper to improve the performance in ship detection in high-resolution synthetic aperture radar (SAR) images. The algorithm introduces SAR formation theories into detection. First, we divide the image into tiles within which the sea background can be treated as homogeneous one. Second, we use a threshold template method to detect candidate ship pixels in each tile. The data model and point spread function model together decide the parameters of the template. Third, group candidate pixels together and exclude false alarms. The template method exploits the relationship between neighbor pixels, which characterise high-resolution images. Experiments validate the algorithm with good performance.

关键词： Synthetic aperture radar Detectors Marine vehicles Image resolution Algorithm design and analysis Object detection

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An efficient TOPS imaging algorithm based on spectral analysis

An efficient TOPS imaging algorithm based on spectral analys...

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

作者： XiaoBei Wang Peng Yin ZeGang Ding XueMei Yan Beijing Key Laboratory of Embedded Real-time Information Processing Technology Beijing Institute of Technology Beijing China CAST Beijing Institute of Spacecraft System Engineering Beijing China

ISBN: (纸本)9781509027095

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 sub-apertures 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： Azimuth Algorithm design and analysis Imaging Antennas time-frequency analysis Bandwidth

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