Multi‐window time–frequency signature reconstruction from undersampled continuous‐wave radar measurements for fall detection

2015 ◽  
Vol 9 (2) ◽  
pp. 173-183 ◽  
Author(s):  
Branka Jokanovic ◽  
Moeness G. Amin ◽  
Yimin D. Zhang ◽  
Fauzia Ahmad
Keyword(s):  
Continuous Wave ◽  
Fall Detection ◽  
Time Frequency ◽  
Wave Radar ◽  
Radar Measurements

scholarly journals Time-Frequency Spectral Signature of Limb Movements and Height Estimation Using Micro-Doppler Millimeter-Wave Radar

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4660
Author(s):  
Yael Balal ◽  
Nezah Balal ◽  
Yair Richter ◽  
Yosef Pinhasi
Keyword(s):  
Millimeter Wave ◽  
Continuous Wave ◽  
Animal Movement ◽  
Doppler Frequency ◽  
Spectral Signature ◽  
Millimeter Wave Radar ◽  
Time Frequency ◽  
Structure And Motion ◽  
W Band ◽  
Wave Radar

We present a technique for the identification of human and animal movement and height using a low power millimeter-wave radar. The detection was based on the transmission of a continuous wave and heterodyning the received signal reflected from the target to obtain micro-Doppler shifts associated with the target structure and motion. The algorithm enabled the extraction of target signatures from typical gestures and differentiated between humans, animals, and other ‘still’ objects. Analytical expressions were derived using a pendulum model to characterize the micro-Doppler frequency shifts due to the periodic motion of the human and animal limbs. The algorithm was demonstrated using millimeter-wave radar operating in the W-band. We employed a time–frequency distribution to analyze the detected signal and classify the type of targets.

scholarly journals Low Probability of Intercept Triangular Modulated Frequency Modulated Continuous Wave Signal Characterization Comparison using the Spectrogram and the Scalogram

2017 ◽  
pp. 37-47
Author(s):  
Daniel L. Stevens ◽  
Stephanie A. Schuckers
Keyword(s):  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Time Frequency ◽  
Novel Approach ◽  
Wave Radar ◽  
Time Frequency Localization ◽  
Low Probability ◽  
Low Probability Of Intercept ◽  
Radar Signals ◽  
Continuous Wave Signal

Digital intercept receivers are currently moving away from Fourier-based analysis and towards classical time-frequency analysis techniques for the purpose of analyzing low probability of intercept radar signals. This paper presents the novel approach of characterizing low probability of intercept frequency modulated continuous wave radar signals through utilization and direct comparison of the Spectrogram versus the Scalogram. Two different triangular modulated frequency modulated continuous wave signals were analyzed. The following metrics were used for evaluation: percent error of: carrier frequency, modulation bandwidth, modulation period, chirp rate, and time-frequency localization (x and y direction). Also used were: percent detection, lowest signal-to-noise ratio for signal detection, and plot (processing) time. Experimental results demonstrate that overall, the Spectrogram produced more accurate characterization metrics than the Scalogram. An improvement in performance may well translate into saved equipment and lives.

scholarly journals A Novel Approach for the Characterization of Triangular Modulated Frequency Modulated Continuous Wave Low Probability of Intercept Radar Signals via Application of the Wigner-Ville Distribution

2021 ◽  
pp. 19-28
Author(s):  
Daniel L. Stevens
Keyword(s):  
Signal Processing ◽  
Continuous Wave ◽  
Processing Technique ◽  
Signal Processing Technique ◽  
Time Frequency ◽  
Novel Approach ◽  
Wave Radar ◽  
Low Probability ◽  
Low Probability Of Intercept ◽  
Radar Signals

Digital intercept receivers are changing from Fourier-based analysis to classical time-frequency analysis techniques for analyzing low probability of intercept radar signals. This paper presents a novel approach of characterizing low probability of intercept triangular modulated frequency modulated continuous wave radar signals through utilization and direct comparison of the signal processing techniques Wigner-Ville Distribution versus the Reassigned Smooth Pseudo Wigner-Ville Distribution. The following metrics were used for evaluation: percent error of: carrier frequency, modulation bandwidth, modulation period, chirp rate, and time-frequency localization (x and y direction). Also used were: percent detection, lowest signal-to-noise ratio for signal detection, and plot (processing) time. Experimental results demonstrate that overall, the Reassigned Smooth Pseudo Wigner-Ville Distribution signal processing technique produced more accurate characterization metrics than the Wigner-Ville Distribution signal processing technique.

scholarly journals Characterisation of human gait using a continuous-wave radar at 24 GHz

2008 ◽  
Vol 6 ◽  
pp. 67-70 ◽  
Author(s):  
C. Hornsteiner ◽  
J. Detlefsen
Keyword(s):  
Moving Objects ◽  
Continuous Wave ◽  
The Body ◽  
Human Gait ◽  
Radar Signal ◽  
Body Parts ◽  
Mean Velocity ◽  
Time Frequency ◽  
Wave Radar ◽  
Wide Range

Abstract. Human locomotion consists of a complex movement of various parts of the body. The reflections generated by body parts with different relative velocities result in different Doppler shifts which can be detected as a superposition with a Continuous-Wave (CW) Radar. A time-frequency transform like the short-time Fourier transform (STFT) of the radar signal allows a representation of the signal in both time- and frequency domain (spectrogram). It can be shown that even during one gait cycle the velocity of the torso, which constitutes the major part of the reflection, is not constant. Further a smaller portion of the signal is reflected from the legs. The velocity of the legs varies in a wide range from zero (foot is on the ground) to a velocity which is higher than that of the torso. The two dominant parameters which characterise the human gait are the step rate and the mean velocity. Both parameters can be deduced from suitable portions of the spectrogram. The statistical evaluation of the two parameters has the potential to be included for discrimination purposes either between different persons or between humans and other moving objects.

A Human Fall Detection System using Continuous Wave Radar

2019 ◽  
Vol 09 ◽  
Author(s):  
Alpesh Vala ◽  
Amit Patel ◽  
Mihir James
Keyword(s):  
High Frequency ◽  
Continuous Wave ◽  
Frequency Synthesizer ◽  
Detection System ◽  
Fall Detection ◽  
Reference Frequency ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Rf Transmitter ◽  
Wave Radar

In this paper contactless human fall detection system has been designed, developed and tested. Continuous wave radar system is implemented at 2.10 GHz of frequency. It consists of transmitter and receiver section. In radio frequency (RF) transmitter system is developed with the use of frequency synthesizer, power amplifier and patch antenna for the transmission of 2.10 GHz. Similarly at the receiver side 2.1001GHz of frequency signal is generated with the use of frequency synthesizer. For the measurement of the fall detection high frequency signal is down converted to 100 KHz of signal with the use of mixer. Number of experiment has been performed for the measurement of fall detection. Here non-living object has been used for the experimental purpose. A fall event has been detected according to the change in the received frequency in respect with the reference frequency.

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