- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Finite-Difference Time-Domain Modeling for Electromagnetic Wave Analysis of Human Voxel Model at Millimeter-Wave Frequencies
摘要： The finite-difference time-domain (FDTD) modeling of a human voxel model at millimeter-wave (mmWave) frequencies is presented. It is very important to develop the proper geometrical and electrical modeling of a human voxel model suitable for accurate electromagnetic (EM) analysis. Although there are many human phantom models available, their voxel resolution is too poor to use for the FDTD study of EM wave interaction with human tissues. In this paper, we develop a proper human voxel model suitable for mmWave FDTD analysis using the voxel resolution enhancement technique and the image smoothing technique. The former can improve the resolution of the human voxel model and the latter can alleviate staircasing boundaries of the human voxel model. Quadratic complex rational function is employed for the electrical modeling of human tissues in the frequency range of 6–100 GHz. Massage passing interface-based parallel processing is also applied to dramatically speed up FDTD calculations. Numerical examples are used to illustrate the validity of the mmWave FDTD simulator developed here for bio electromagnetics studies.
关键词： human tissue,electromagnetic wave,Doppler radar,dispersion model,bioelectromagnetics,Finite-difference time-domain (FDTD) method,parallel processing
更新于2025-09-23 15:23:52
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Improved Sparse Adaptive Algorithms for Accurate Non-contact Heartbeat Detection Using Time-Window-Variation Technique
摘要： Recently, a sparse adaptive algorithm termed zero-attracting sign least-mean-square (ZA-SLMS), has been clarified to be able to reconstruct robustly heartbeat spectrum by Doppler radar signal. However, since the strengths of noise evidently differ under different body motions, the sparse heartbeat spectra cannot be always acquired accurately by the constant regularization parameter (REPA) that balances the gradient correction and the sparse penalty, applying in the ZA-SLMS algorithm. In this paper, an improved ZA-SLMS algorithm is proposed by introducing adaptive REPA (AREPA), where the proportion of sparse penalty is adjusted based on the standard deviation of radar data. Moreover, to enhance the stability of heartbeat detection, a time-window-variation (TWV) technique is further introduced in the improved ZA-SLMS algorithm, considering the fact that the position of spectral peak associated with the heart rate (HR) is stable when the length of time window changes within a short period. Experimental results measured against five subjects validated that our proposal reliably improves the error of HR estimation than the standard ZA-SLMS algorithm.
关键词： heartbeat detection,time-window-variation,Doppler radar,regularization parameter,sparse adaptive algorithm
更新于2025-09-23 15:23:52
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - Long range-Doppler Demonstration of a 95 GHz FMCW Radar
摘要： We present the first demonstration of a thermal-noise-limited 95 GHz frequency modulated continuous wave (FMCW) Doppler radar with high (1 Watt) transmit power and long-range Doppler detection capabilities. The 95 GHz radar is part of (Gas And Ice Spectrometer/Radar) instrument to probe the dynamics and distribution of cometary jets and plumes in icy bodies in the solar system. Radar measurements were carried out using a variety of targets at different range and velocities, such as freeway cars, clouds, rain and hillsides, to test the range and Doppler capabilities. The compact design (a single 15 cm diameter primary antenna), and high quality data presented in this paper makes this 95 GHz FMCW radar uniquely suitable for future space missions for Planetary and Earth Science applications.
关键词： Doppler radar,FMCW radar
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Study of Room Temperature Photoluminescence For 1-stage Co-Evaporated Ultra-Thin Cu(In,Ga)Se <sub/>2</sub> Solar Cells
摘要： In this paper, we investigate the feasibility of recognizing human hand gestures using micro-Doppler signatures measured by Doppler radar with a deep convolutional neural network (DCNN). Hand gesture recognition using radar can be applied to control electronic appliances. Compared with an optical recognition system, radar can work regardless of light conditions and it can be embedded in a case. We classify ten different hand gestures, with only micro-Doppler signatures on spectrograms without range information. The ten gestures, which included swiping from left to right, swiping from right to left, rotating clockwise, rotating counterclockwise, pushing, double pushing, holding, and double holding, were measured using Doppler radar and their spectrograms investigated. A DCNN was employed to classify the spectrograms, with 90% of the data utilized for training and the remaining 10% for validation. After ?ve-fold validation, the classi?cation accuracy of the proposed method was found to be 85.6%. With seven gestures, the accuracy increased to 93.1%.
关键词： Doppler radar,micro-Doppler signatures,Hand gesture,deep convolutional neural networks
更新于2025-09-23 15:19:57
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[IEEE 2018 5th International Conference on Information Science and Control Engineering (ICISCE) - Zhengzhou, China (2018.7.20-2018.7.22)] 2018 5th International Conference on Information Science and Control Engineering (ICISCE) - A Portable 24GHz Doppler Radar System for Distant Human Vital Sign Monitoring
摘要： Vital sign detection using Doppler radar can be potentially applied in health care and home monitoring. While most of developed Doppler radars are designed in laboratory environments, this paper introduces a portable 24 GHz Doppler radar using commercial modules at low cost. The Doppler radar system adopts the commercially available 24GHz transceiver module to obtain analog quadrature signals, the signals are digitalized using analog-to-digital conversion in microcontroller, then sent to laptop or mobile phone via a series to WIFI module. All the modules are implemented on a printed circuit board to achieve the small size. Experiments validate that the Doppler radar can sense human respiration and heartbeat rates successfully using time frequency based signal processing algorithms.
关键词： vital sign detection,Doppler radar,time frequency analysis,heartbeat and respiration
更新于2025-09-19 17:15:36
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[IEEE 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - HangZhou, China (2018.9.5-2018.9.7)] 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - RCS Reduction of 2??2 Microstrip Antenna Array Using All Dielectric Metasurface
摘要： In this paper, we investigate the feasibility of recognizing human hand gestures using micro-Doppler signatures measured by Doppler radar with a deep convolutional neural network (DCNN). Hand gesture recognition using radar can be applied to control electronic appliances. Compared with an optical recognition system, radar can work regardless of light conditions and it can be embedded in a case. We classify ten different hand gestures, with only micro-Doppler signatures on spectrograms without range information. The ten gestures, which included swiping from left to right, swiping from right to left, rotating clockwise, rotating counterclockwise, pushing, double pushing, holding, and double holding, were measured using Doppler radar and their spectrograms investigated. A DCNN was employed to classify the spectrograms, with 90% of the data utilized for training and the remaining 10% for validation. After ?ve-fold validation, the classi?cation accuracy of the proposed method was found to be 85.6%. With seven gestures, the accuracy increased to 93.1%.
关键词： Doppler radar,micro-Doppler signatures,Hand gesture,deep convolutional neural networks
更新于2025-09-16 10:30:52
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - Comparisons Between Simulated and Measured X-band Signatures of Quad-, Hexa- and Octocopters
摘要： This paper presents and compares finite element method (FEM) and method of moments (MoM) monostatic radar cross-section (RCS) simulation results for an example quadcopter, hexacopter and octocopter at X-band, as well as comparing the simulations against measurements for quad- and hexacopters. In particular we explore the extent to which simplified CAD models can be used to estimate the scattering from multi-rotor unmanned aerial vehicles (UAVs). We also consider the importance of model complexity for micro-Doppler rotor simulations.
关键词： Doppler radar,radar cross-sections,Radar
更新于2025-09-11 14:15:04
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A Stochastic Gradient Approach for Robust Heartbeat Detection with Doppler Radar Using Time-Window-Variation Technique
摘要： Heart rate variability (HRV) indicates health condition and mental stress. The development of non-contact heart rate (HR) monitoring technique with Doppler radar is attracting great attentions. However, the performance of heartbeat detection via radar signal easily degrades, due to respiration and body motion. In this paper, first, a stochastic gradient approach is applied to reconstruct high-resolution spectrum of heartbeat, by proposing the zero-attracting sign least-mean-square (ZA-SLMS) algorithm. To correct the quantized gradient of cost function, and penalize the sparse constraint on the updating spectrum, more accurate heartbeat spectrum is reconstructed. Then, to better adapt to the noises with different strengths caused by subjects’ movements, an adaptive regularization parameter (AREPA) is introduced in the ZA-SLMS algorithm as an improved variant, which can adaptively regulate the proportion between gradient correction and sparse penalty. Moreover, in view of the stability of location of spectral peak associated with HR when the size of time window slightly changes, a time-window-variation (TWV) technique is further incorporated in the improved ZA-SLMS (IZA-SLMS) algorithm, for more stable HR estimation. Through the experiments on five subjects, our proposal is demonstrated to bring a significant improvement of accuracy against existing detection methods. Specifically, the IZA-SLMS algorithm with TWV achieves the smallest average error of 3.79 beats per minute (BPM), when subjects type with a laptop.
关键词： Doppler radar,Non-contact heartbeat detection,sparse spectrum reconstruction (SSR),adaptive filter,time-window-variation (TWV),heart rate (HR)
更新于2025-09-09 09:28:46
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[IEEE 2018 24th International Conference on Pattern Recognition (ICPR) - Beijing, China (2018.8.20-2018.8.24)] 2018 24th International Conference on Pattern Recognition (ICPR) - Human Gait Recognition with Micro-Doppler Radar and Deep Autoencoder
摘要： The micro-Doppler signals from moving objects contain useful information about their motions. This paper introduces a novel approach for human gait recognition based on backscattered signals from a micro-Doppler radar. Three different signal techniques are utilized for the extraction of micro-Doppler features via time-frequency and time-scale representations. To classify the human motions into various types, this paper presents a deep autoencoder with the use of local patches extracted along the spectrogram and scalogram. The network configuration and the learning parameters of the deep autoencoder, which are considered as hyperparameters, are optimized by a Bayesian optimization algorithm. Experimental results produced by the proposed technique on real radar data show a significant improvement compared to several existing approaches.
关键词： Short-time Fourier Transform,micro-Doppler radar,deep autoencoder,S-method,wavelet transform,Bayesian optimization
更新于2025-09-09 09:28:46
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Improved rain-rate and drop-size retrievals from airborne and spaceborne Doppler radar
摘要： Satellite radar remote-sensing of rain is important for quantifying of the global hydrological cycle, atmospheric energy budget, and many microphysical cloud and precipitation processes; however, radar estimates of rain rate are sensitive to assumptions about the rain drop size distribution. The upcoming EarthCARE satellite will feature a 94 GHz Doppler radar alongside lidar and radiometer instruments, presenting opportunities for enhanced global retrievals of the rain drop size distribution. In this paper we demonstrate the capability to retrieve both rain rate and a parameter of the rain drop size distribution from an airborne 94 GHz Doppler radar using CAPTIVATE, the variational retrieval algorithm developed for EarthCARE radar–lidar synergy. For a range of rain regimes observed during the Tropical Composition, Cloud and Climate Coupling (TC4) field campaign in the eastern Pacific in 2007, we explore the contributions of Doppler velocity and path-integrated attenuation (PIA) to the retrievals, and evaluate the retrievals against independent measurements from a second, less attenuated, Doppler radar aboard the same aircraft. Retrieved drop number concentration varied over five orders of magnitude between light rain from melting ice, and warm rain from liquid clouds. Doppler velocity can be used to estimate rain rate over land, and retrievals of rain rate and drop number concentration are possible in profiles of light rain over land; in moderate warm rain, drop number concentration can be retrieved without Doppler velocity. These results suggest that EarthCARE rain retrievals facilitated by Doppler radar will make substantial improvements to the global understanding of the interaction of clouds and precipitation.
关键词： CAPTIVATE,satellite radar remote-sensing,EarthCARE,rain rate,path-integrated attenuation,Doppler radar,retrieval algorithm,drop size distribution
更新于2025-09-04 15:30:14