Dr. Victor C. Chen Profile

Dr. Victor C. Chen

Electronics Engineer

SPIE Involvement:

Author | Instructor

Publications (42)

Proceedings Article | 1 April 2003 Paper

Micro-Doppler effect of micromotion dynamics: a review

Victor Chen

Proceedings Volume 5102, (2003) https://doi.org/10.1117/12.488855

KEYWORDS: Radar, Doppler effect, Gait analysis, Time-frequency analysis, Synthetic aperture radar, Reflectors, Combustion, Mathematics, Modulation, Microwave radiation

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SPIE Journal Paper | 1 January 2003

Adaptive filtering approach to chirp estimation and inverse synthetic aperture radar imaging of maneuvering targets

Genyuan Wang, Xiang-Gen Xia, Victor Chen

OE, Vol. 42, Issue 01, (January 2003) https://doi.org/10.1117/12.10.1117/1.1526842

KEYWORDS: Radar, Digital filtering, Radar imaging, Detection and tracking algorithms, Synthetic aperture radar, Optical filters, Image filtering, Electronic filtering, Fourier transforms, Optical engineering

Proceedings Article | 7 August 2002 Paper

Radar detection of multiple moving targets in clutter using time-frequency radon transform

Victor Chen

Proceedings Volume 4728, (2002) https://doi.org/10.1117/12.478534

KEYWORDS: Target detection, Doppler effect, Radar, Radon transform, Time-frequency analysis, Signal to noise ratio, Detection and tracking algorithms, Antennas, Analytical research, Reflectivity

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Proceedings Article | 8 March 2002 Paper

Applications of rotational time-frequency transforms to radar imaging of moving targets

Victor Chen

Proceedings Volume 4738, (2002) https://doi.org/10.1117/12.458737

KEYWORDS: Time-frequency analysis, Transform theory, Radon transform, Target detection, Synthetic aperture radar, Fourier transforms, Radar imaging, Signal detection, Commercial off the shelf technology, Electronic filtering

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Proceedings Article | 8 March 2002 Paper

Moving-target detection in over-the-horizon radar using adaptive chirplet transform

Genyuan Wang, Xiang-Gen Xia, Benjamin Root, Victor Chen

Proceedings Volume 4738, (2002) https://doi.org/10.1117/12.458736

KEYWORDS: Target detection, Doppler effect, Signal detection, Fourier transforms, Radar, Detection and tracking algorithms, Radar signal processing, Darmstadtium, Signal processing, Electronic filtering

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Proceedings Article | 26 March 2001 Paper

Radar signatures of rotor blades

Victor Chen

Proceedings Volume 4391, (2001) https://doi.org/10.1117/12.421231

KEYWORDS: Radar, Modulation, Time-frequency analysis, Frequency modulation, Doppler effect, Target recognition, Fourier transforms, Phase shift keying, Solid modeling, Backscatter

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Proceedings Article | 26 March 2001 Paper

Adaptive chirp-Fourier transform for chirp estimation with applications in ISAR imaging of maneuvering targets

Xiang-Gen Xia, Genyuan Wang, Victor Chen

Proceedings Volume 4391, (2001) https://doi.org/10.1117/12.421219

KEYWORDS: Radar imaging, Radar, Lithium, Fourier transforms, Detection and tracking algorithms, Digital filtering, Synthetic aperture radar, Image resolution, Interference (communication), Image filtering

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Proceedings Article | 13 November 2000 Paper

Information theoretic measure for ISAR imagery focusing

Yun He, A. Ben Hamza, A. Hamid Krim, Victor Chen

Proceedings Volume 4116, (2000) https://doi.org/10.1117/12.406526

KEYWORDS: Radar, Time-frequency analysis, Synthetic aperture radar, Reflectivity, Image information entropy, Image resolution, Signal attenuation, Detection and tracking algorithms, Radar imaging, Antennas

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Proceedings Article | 24 August 2000 Paper

Detection, location, and imaging of fast moving targets using multifrequency antenna array SAR

Genyuan Wang, Xiang-Gen Xia, Victor Chen, Ralph Fiedler

Proceedings Volume 4053, (2000) https://doi.org/10.1117/12.396383

KEYWORDS: Antennas, Synthetic aperture radar, Target detection, Radar, CRTs, Detection and tracking algorithms, Imaging arrays, Fourier transforms, Image resolution, Roads

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Detection, location and SAR imaging of moving targets in clutter have attracted much attention. Locations of moving targets in the SAR image are determined not only by their geometric locations but also by their velocities that cause their SAR images de-focused, smeared, and mis-located in the azimuth dimension. Furthermore, the clutters may cause the detection of moving targets more difficult. Several antenna array based algorithms have been proposed to re-locate the moving targets in the SAR image. With a linear antenna array, the clutters may be suppressed using multiple phase centers. However, there are only two parameters involved in a linear antenna array, i.e., number of receiving antennas and the distance between two adjacent antennas. These two parameters physically limit the capability to detect the accurate locations of fast moving targets and such as vehicles, and only slowly moving targets, such as walking people, can be correctly re-located. In this paper, we propose an antenna array approach where transmitting single wavelength signals are generalized to transmitting multiple wavelength signals (called multi-frequency antenna array SAR). We show that, using multi-frequency antenna array SAR, not only the clutters can be suppressed but also locations of both slow and fast moving targets can be accurately estimated. For example, using two-frequency antenna array SAR system with wavelengths (lambda) ₁ equals 0.03 m and (lambda) ₂ equals 0.05 m, the maximal moving target velocity in the range direction is 1 5 m/s while using single frequency antenna array SAR system with wave length (lambda) ₁ equals 0.03 m or (lambda) ₂ equals 0.05 m, the maximal moving target velocity in the range direction are 3 m/s or 5 m/s, respectively. A robust Chinese Remainder Theorem (CRT) is developed and used for the location of fast and slowly moving targets. Simulations of SAR imaging of ground moving targets are presented to illustrate the effectiveness of the multi-frequency antenna array SAR imaging algorithm.

Proceedings Article | 24 August 2000 Paper

Robust autofocus algorithm for ISAR imaging of moving targets

Jian Li, Renbiao Wu, Victor Chen

Proceedings Volume 4053, (2000) https://doi.org/10.1117/12.396331

KEYWORDS: Detection and tracking algorithms, Motion estimation, Radar, Automatic target recognition, Synthetic aperture radar, Data modeling, Radar imaging, Image quality, Evolutionary algorithms, Target recognition

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Proceedings Article | 5 April 2000 Paper

Time frequency signatures of micro-Doppler phenomenon for feature extraction

Victor Chen, Ronald Lipps

Proceedings Volume 4056, (2000) https://doi.org/10.1117/12.381683

KEYWORDS: Radar, Reflectors, Time-frequency analysis, Doppler effect, Target recognition, Target detection, Modulation, Feature extraction, Fourier transforms, Analytical research

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Proceedings Article | 2 November 1999 Paper

Iterative direction-of-arrival estimation with wideband chirp signals

Genyuan Wang, Xiang-Gen Xia, Victor Chen

Proceedings Volume 3807, (1999) https://doi.org/10.1117/12.367665

KEYWORDS: Time-frequency analysis, Sensors, Signal processing, Algorithm development, Fourier transforms, Transform theory, Interference (communication), Radar, Coastal modeling, Signal to noise ratio

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Proceedings Article | 29 September 1999 Paper

Effect of roll, pitch, and yaw motions on ISAR imaging

Victor Chen, William Miceli

Proceedings Volume 3810, (1999) https://doi.org/10.1117/12.364069

KEYWORDS: Radar, Doppler effect, Detection and tracking algorithms, Image processing, Signal processing, Radar imaging, Reflectivity, Analytical research, Composites, Radar signal processing

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Proceedings Article | 29 September 1999 Paper

Multifrequency VSAR imaging of moving targets

Genyuan Wang, Xiang-Gen Xia, Victor Chen

Proceedings Volume 3810, (1999) https://doi.org/10.1117/12.364070

KEYWORDS: Radar, Antennas, Receivers, Synthetic aperture radar, Fourier transforms, Doppler effect, Radar imaging, Target detection, Transmitters, Image resolution

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Proceedings Article | 29 September 1999 Paper

Comparison of high-resolution ISAR imagery from measured data and synthetic signatures

Junfei Li, Yuanxun Wang, Rajan Bhalla, Hao Ling, Victor Chen

Proceedings Volume 3810, (1999) https://doi.org/10.1117/12.364077

KEYWORDS: Time-frequency analysis, Image processing, Radar, Global Positioning System, Detection and tracking algorithms, Motion measurement, Computer simulations, Radar imaging, Visualization, Doppler effect

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Proceedings Article | 13 August 1999 Paper

Dual-speed SAR imaging of moving targets

Genyuan Wang, Xiang-Gen Xia, Victor Chen

Proceedings Volume 3721, (1999) https://doi.org/10.1117/12.357629

KEYWORDS: Radar, Synthetic aperture radar, Doppler effect, Error analysis, Motion estimation, Target detection, Imaging systems, Radar imaging, Device simulation, Fourier transforms

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Proceedings Article | 22 March 1999 Paper

Model-based time-frequency analysis

Shie Qian, Victor Chen

Proceedings Volume 3723, (1999) https://doi.org/10.1117/12.342959

KEYWORDS: Time-frequency analysis, Model-based design, Radar, Data modeling, Biomedical optics, Feature extraction, Automatic target recognition, Zoom lenses, Coastal modeling, Radar signal processing

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Proceedings Article | 14 October 1998 Paper

Signal-to-noise ratio analysis in the joint time-frequency domain for ISAR imaging

Genyuan Wang, Xiang-Gen Xia, Victor Chen

Proceedings Volume 3462, (1998) https://doi.org/10.1117/12.326743

KEYWORDS: Signal to noise ratio, Fourier transforms, Radar, Interference (communication), Time-frequency analysis, Transform theory, Radar imaging, Doppler effect, Signal detection, Signal processing

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Proceedings Article | 14 October 1998 Paper

Application of adaptive joint time-frequency processing to ISAR image enhancement and Doppler feature extraction for targets with rotating parts

Yuanxun Wang, Hao Ling, Victor Chen

Proceedings Volume 3462, (1998) https://doi.org/10.1117/12.326742

KEYWORDS: Doppler effect, Time-frequency analysis, Scattering, Detection and tracking algorithms, Signal processing, Radar, Image processing, Image enhancement, Computer simulations, Signal detection

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Proceedings Article | 26 March 1998 Paper

ISAR imaging of targets with fast rotating parts using adaptive joint time-frequency processing

Yuanxun Wang, Hao Ling, Victor Chen

Proceedings Volume 3391, (1998) https://doi.org/10.1117/12.304905

KEYWORDS: Doppler effect, Time-frequency analysis, Scattering, Image processing, Detection and tracking algorithms, Radar, Signal processing, Fourier transforms, Computer simulations, Data modeling

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Proceedings Article | 26 March 1998 Paper

Time-frequency analysis of SAR images with ground moving targets

Victor Chen

Proceedings Volume 3391, (1998) https://doi.org/10.1117/12.304879

KEYWORDS: Synthetic aperture radar, Doppler effect, Time-frequency analysis, Radar, Image acquisition, Image analysis, Radar imaging, Image compression, Target detection, Analytical research

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Proceedings Article | 24 September 1997 Paper

Radar imaging of multiple moving targets

Victor Chen, Zhen Zhong Lu

Proceedings Volume 3161, (1997) https://doi.org/10.1117/12.279463

KEYWORDS: Doppler effect, Time-frequency analysis, Detection and tracking algorithms, Radar, Radar imaging, Image acquisition, Transform theory, Fourier transforms, Image resolution, Phase compensation

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Proceedings Article | 28 July 1997 Paper

Time-frequency-based ISAR image formation technique

Victor Chen

Proceedings Volume 3070, (1997) https://doi.org/10.1117/12.281581

KEYWORDS: Time-frequency analysis, Doppler effect, Fourier transforms, Transform theory, Radar, Image acquisition, Image processing, Image resolution, Detection and tracking algorithms, Image restoration

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Proceedings Article | 3 April 1997 Paper

Time-frequency separation of multiple moving radar targets

Zhen Zhong Lu, Anna Baraniecki, Victor Chen

Proceedings Volume 3078, (1997) https://doi.org/10.1117/12.271716

KEYWORDS: Radar, Detection and tracking algorithms, Time-frequency analysis, Doppler effect, Transform theory, Radar imaging, Computer simulations

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Proceedings Article | 3 April 1997 Paper

Block time-recursive algorithm for the computation of short-time Fourier transform and its application to ISAR imaging

Chao Lu, Victor Chen

Proceedings Volume 3078, (1997) https://doi.org/10.1117/12.271732

KEYWORDS: Fourier transforms, Radar, Image processing, Transform theory, Radium, Synthetic aperture radar, Computer simulations, Doppler effect, Image resolution, Chaos

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Proceedings Article | 3 April 1997 Paper

ISAR image formation and feature extraction using adaptive joint time-frequency processing

Hao Ling, Yuanxun Wang, Victor Chen

Proceedings Volume 3078, (1997) https://doi.org/10.1117/12.271734

KEYWORDS: Time-frequency analysis, Scattering, Image processing, Doppler effect, Feature extraction, Detection and tracking algorithms, Image enhancement, Algorithm development, Image acquisition, Clouds

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Proceedings Article | 3 April 1997 Paper

Radar range profile analysis with natural frame time-frequency representation

Victor Chen

Proceedings Volume 3078, (1997) https://doi.org/10.1117/12.271736

KEYWORDS: Time-frequency analysis, Radar, Feature extraction, Solids, Scattering, Analytical research, Fourier transforms, Niobium, Image resolution, Target recognition

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SPIE Journal Paper | 1 April 1997

Applications of time-frequency processing to radar imaging

Victor Chen

OE, Vol. 36, Issue 04, (April 1997) https://doi.org/10.1117/12.10.1117/1.601304

KEYWORDS: Doppler effect, Time-frequency analysis, Radar, Fourier transforms, Scattering, Image resolution, Image processing, Clouds, Reflectivity, Radar imaging

Proceedings Article | 5 November 1996 Paper

Adaptive time-frequency ISAR processing

Victor Chen

Proceedings Volume 2845, (1996) https://doi.org/10.1117/12.257216

KEYWORDS: Time-frequency analysis, Doppler effect, Fourier transforms, Image processing, Radar, Image resolution, Radar imaging, Signal analyzers, Associative arrays, Zoom lenses

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Proceedings Article | 10 June 1996 Paper

Three-dimensional ground truth reconstruction using 2D ISAR imagery

Sharon Wang, Yishuo Huang, Victor Chen

Proceedings Volume 2757, (1996) https://doi.org/10.1117/12.242027

KEYWORDS: 3D modeling, 3D image processing, 3D acquisition, Feature extraction, 3D image reconstruction, Sensors, Wavelets, 3D vision, Visualization, Synthetic aperture radar

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Proceedings Article | 22 March 1996 Open Access

Applications of time-frequency processing to radar imaging

Victor Chen

Proceedings Volume 2762, (1996) https://doi.org/10.1117/12.236004

KEYWORDS: Radar, Doppler effect, Time-frequency analysis, Fourier transforms, Image processing, Image enhancement, Radar imaging, Image resolution, Scattering, Reflectivity

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High resolution radar image is always demanded. To achieve high resolution, wideband signal and longer imaging time are required. However, due to time-varying behavior of returned radar signals and due to multiple backscattering behavior of targets, radar image resolution can be significantly degraded and images become blurred. The conventional radar processor uses the Fourier transform to retrieve Doppler information. In order to use the Fourier transform adequately, some restrictions must be applied: the scatterers must remain in their range cells and their Doppler frequency contents should be stationary during the entire imaging time duration. However, due to the target's complex motion, the Doppler frequency contents are actually time-varying. Therefore, the Doppler spectrum obtained from the Fourier transform becomes smeared, and, thus, the resolution of the radar image is degraded. However, the restrictions of the Fourier processing can be lifted if the Doppler information can be retrieved with a method which does not require stationary Doppler spectrum. Therefore, the image blurring caused by the time-varying Doppler spectrum can be resolved without applying sophisticated motion compensation. By replacing the conventional Fourier transform with a time-frequency transform, a 2-D range-Doppler Fourier frame becomes a 3- D time-range-Doppler cube. By sampling in time, a time sequence of 2-D range-Doppler images can be viewed. Each individual time-sampled image from the cube provides superior image resolution and also enhanced signal-to-noise ratio. When the target contains cavities or duct-type structures, these scattering mechanisms appear in radar images as blurred clouds extended in range dimension. It is very useful to combine adaptive time-frequency wavelet transform with the radar imaging technique so that the 'clouds' can be removed and their resonance frequencies can be identified. By applying time-frequency processing for each cross-range lines of radar image, a 3-D range-Doppler-frequency cube is generated. The frequency slices of the cube provide information for identifying scattering centers as well as resonance frequencies.

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Proceedings Article | 22 March 1996 Paper

CFAR detection and extraction of unknown signal in noise with time-frequency Gabor transform

Victor Chen, Shie Qian

Proceedings Volume 2762, (1996) https://doi.org/10.1117/12.236002

KEYWORDS: Signal detection, Time-frequency analysis, Interference (communication), Signal to noise ratio, Signal processing, Environmental sensing, Joint transforms, Digital signal processing, Radar, Fourier transforms

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Proceedings Article | 22 March 1996 Paper

Wavelet matrices: algorithms and applications

Zhen Zhong Lu, Victor Chen, Harry Wechsler

Proceedings Volume 2762, (1996) https://doi.org/10.1117/12.236035

KEYWORDS: Wavelets, Convolution, Matrices, Filtering (signal processing), Model-based design, Reconstruction algorithms, Electronic filtering, Wavelet transforms, Bandpass filters, Signal processing

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Proceedings Article | 18 August 1995 Paper

Clutter suppression using wavelet shrinkage

Victor Chen

Proceedings Volume 2562, (1995) https://doi.org/10.1117/12.216946

KEYWORDS: Wavelets, Discrete wavelet transforms, Radar, Wavelet transforms, Linear filtering, Signal processing, Smoothing, Electronic filtering, Interference (communication), Detection theory

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Proceedings Article | 6 April 1995 Paper

Reconstruction of inverse synthetic aperture radar image using adaptive time-frequency wavelet transform

Victor Chen

Proceedings Volume 2491, (1995) https://doi.org/10.1117/12.205404

KEYWORDS: Doppler effect, Time-frequency analysis, Image processing, Wavelets, Wavelet transforms, Super resolution, Image resolution, Reflectors, Fourier transforms, Synthetic aperture radar

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SPIE Journal Paper | 1 July 1994

Radar ambiguity function, time-varying matched filter, and optimum wavelet correlator

Victor Chen

OE, Vol. 33, Issue 07, (July 1994) https://doi.org/10.1117/12.10.1117/12.172252

KEYWORDS: Electronic filtering, Wavelets, Radar, Wavelet transforms, Doppler effect, Time-frequency analysis, Optical correlators, Image processing, Signal to noise ratio, Signal processing

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Proceedings Article | 15 March 1994 Paper

Radar ambiguity function, time-varying matched filter, and optimum wavelet correlator

Victor Chen

Proceedings Volume 2242, (1994) https://doi.org/10.1117/12.170037

KEYWORDS: Electronic filtering, Radar, Wavelets, Optical correlators, Wavelet transforms, Time-frequency analysis, Signal to noise ratio, Doppler effect, Synthetic aperture radar, Interference (communication)

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Proceedings Article | 15 March 1994 Paper

Gabor wavelet pyramid for depth recovery

Thomas Tsao, Victor Chen

Proceedings Volume 2242, (1994) https://doi.org/10.1117/12.170020

KEYWORDS: Wavelets, Visualization, Image fusion, Image filtering, Image restoration, Phase shifts, Computer architecture, Parallel computing, Information visualization, Eye

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Proceedings Article | 1 November 1993 Paper

Gabor-wavelet pyramid for the extraction of image flow

Victor Chen, Thomas Tsao

Proceedings Volume 2034, (1993) https://doi.org/10.1117/12.162057

KEYWORDS: Image filtering, Motion estimation, Motion models, Feature extraction, Visualization, Systems modeling, Linear filtering, Visual process modeling, Motion detection, Image analysis

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Proceedings Article | 1 November 1993 Paper

Detection of signal in noise using optimum wavelet receiver

Victor Chen

Proceedings Volume 2034, (1993) https://doi.org/10.1117/12.162078

KEYWORDS: Signal detection, Receivers, Wavelets, Interference (communication), Signal to noise ratio, Discrete wavelet transforms, Time-frequency analysis, Signal processing, Error analysis, Thulium

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Proceedings Article | 3 September 1993 Paper

Detection of radar signal in noise using optimum time-frequency receiver

Victor Chen

Proceedings Volume 1955, (1993) https://doi.org/10.1117/12.154989

KEYWORDS: Signal detection, Wavelets, Time-frequency analysis, Receivers, Radar, Interference (communication), Wavelet transforms, Electronic filtering, Discrete wavelet transforms, Signal to noise ratio

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Proceedings Article | 1 July 1990 Paper

Neural network for computing optical flow from spatio-temporal frequencies

Thomas Tsao, Victor Chen, John Libert, Haw-Jye Shyu

Proceedings Volume 1215, (1990) https://doi.org/10.1117/12.18090

KEYWORDS: Sensors, Neural networks, Optical flow, Image sensors, Spatial frequencies, Motion analysis, Optical computing, Computer networks, Visualization, Image analysis

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Showing 5 of 42 publications

Conference Committee Involvement (4)

Independent Component Analyses, Wavelets, Unsupervised Smart Sensors, and Neural Networks IV

19 April 2006 | Orlando (Kissimmee), Florida, United States

Independent Component Analyses, Wavelets, Unsupervised Smart Sensors, and Neural Networks III

30 March 2005 | Orlando, Florida, United States

Independent Component Analyses, Wavelets, Unsupervised Smart Sensors, and Neural Networks II

14 April 2004 | Orlando, Florida, United States

Independent Component Analyses, Wavelets, and Neural Networks

22 April 2003 | Orlando, Florida, United States

Course Instructor

SC1031: Radar Micro-Doppler Signatures - Principles and Applications

This course explains basic principles and applications of the micro-Doppler signatures of radar targets. A micro-Doppler signature is a distinctive characteristic of the intricate frequency modulations generated from each component part of a target and is represented in the joint time and Doppler frequency domain. Micro-Doppler signatures provide unique target features that are complementary to those made available by existing methods. The primary goals of the course are to describe the radar micro-Doppler effect, the mathematical and dynamic models of targets with various motions and the analysis of micro-Doppler signatures. The course will present current applications of radar micro-Doppler signature analysis to target detection, characterization, and classification. Radar data returned from rigid body motion and non-rigid body motion will be used in the presentation examples as well as simulations. Examples are shown from state-of-the-art radars in both anechoic chambers and realistic environments.

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