scholarly journals BlueFMCW: Random Frequency Hopping Radar for Mitigation of Interference and Spoofing

2021 ◽  
Author(s):  
Thomas Moon ◽  
Jounsup Park ◽  
Seungmo Kim
Keyword(s):  
Continuous Wave ◽  
Alignment Algorithm ◽  
Security Attacks ◽  
Fmcw Radar ◽  
Central Piece ◽  
Phase Alignment ◽  
Random Frequency ◽  
Phase Discontinuity ◽  
Multiple Frequencies ◽  
Active Attacks

Abstract Radars form a central piece in a variety of emerging applications requiring higher degrees of localization. However, two problems are anticipated as more radars are deployed: viz., (i) inter-radar interference and (ii) security attacks. While many prior proposals have addressed the problems, no work in the radar literature addressed them simultaneously. In this context, we introduce a novel frequency-modulated continuous-wave (FMCW) radar scheme (namely, BlueFMCW) that aims to alleviate the damage from interference and active attacks (e.g., spoofing). The technique designs that the waveform randomly hops across multiple frequencies to dilute the damage at a certain frequency. Moreover, we propose a phase alignment algorithm to remove the phase discontinuity while combining the beat signals from the randomly-hopped chirps. The simulation results show that the proposed technique can efficiently mitigate the interference and spoofing signals in various scenarios without costing its resolution.

scholarly journals Presence and Biomass Information Extraction from Highly Uncertain Data of an Experimental Low-Range Insect Radar Setup

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 452
Author(s):  
Alexey Noskov ◽  
Sebastian Achilles ◽  
Jörg Bendix
Keyword(s):  
Continuous Wave ◽  
Uncertain Data ◽  
Light Trap ◽  
Global Solutions ◽  
Absolute Magnitude ◽  
Real Field ◽  
Biomass Estimation ◽  
60 Ghz ◽  
Fmcw Radar ◽  
Insect Monitoring

Systematic, practicable, and global solutions are required for insect monitoring to address species decline and pest management concerns. Compact frequency-modulated continuous-wave (FMCW) radar can facilitate these processes. In this work, we evaluate a 60 GHz low-range FMCW radar device for its applicability to insect monitoring. Initial tests showed that radar parameters should be carefully selected. We defined optimal radar configuration during the first experiment and developed a methodology for individual target observation. In the second experiment, we tried various individual-insect targets, including small ones. The third experiment was devoted to mass-insect-target detection. All experiments were intentionally conducted in very uncertain conditions to make them closer to a real field situation. A novel parameter, the Sum of Sequential Absolute Magnitude Differences (SSAMD), has been proposed for uncertainty reduction and noisy data processing. SSAMD enables insect target presence detection and biomass estimation. We have defined ranges of SSAMD for distinguishing noise, insects, and other larger targets (e.g., bats, birds, or other larger objects). We have provided evidence of the high correlation between insect numbers and the average of SSAMD values proving the biomass estimation possibility. This work confirms that such radar devices can be used for insect monitoring. We plan to use the evaluated system assembled with a light trap for real fieldwork in the future.

scholarly journals FPGA Implementation of an Efficient FFT Processor for FMCW Radar Signal Processing

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6443
Author(s):  
Jinmoo Heo ◽  
Yongchul Jung ◽  
Seongjoo Lee ◽  
Yunho Jung
Keyword(s):  
Signal Processing ◽  
Detection Rate ◽  
Continuous Wave ◽  
Vital Signs ◽  
Radar Signal ◽  
Radar Signal Processing ◽  
Fmcw Radar ◽  
Design And Implementation ◽  
Fft Processor ◽  
Point Operator

This paper presents the design and implementation results of an efficient fast Fourier transform (FFT) processor for frequency-modulated continuous wave (FMCW) radar signal processing. The proposed FFT processor is designed with a memory-based FFT architecture and supports variable lengths from 64 to 4096. Moreover, it is designed with a floating-point operator to prevent the performance degradation of fixed-point operators. FMCW radar signal processing requires windowing operations to increase the target detection rate by reducing clutter side lobes, magnitude calculation operations based on the FFT results to detect the target, and accumulation operations to improve the detection performance of the target. In addition, in some applications such as the measurement of vital signs, the phase of the FFT result has to be calculated. In general, only the FFT is implemented in the hardware, and the other FMCW radar signal processing is performed in the software. The proposed FFT processor implements not only the FFT, but also windowing, accumulation, and magnitude/phase calculations in the hardware. Therefore, compared with a processor implementing only the FFT, the proposed FFT processor uses 1.69 times the hardware resources but achieves an execution time 7.32 times shorter.

scholarly journals Asynchronous electric field visualization using an integrated multichannel electro-optic probe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shintaro Hisatake ◽  
Junpei Kamada ◽  
Yuya Asano ◽  
Hirohisa Uchida ◽  
Makoto Tojo ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Near Field ◽  
Horn Antenna ◽  
Optimal Placement ◽  
Radar Signal ◽  
Radiation Patterns ◽  
Practical Applications ◽  
Fmcw Radar ◽  
Realistic Situation ◽  
Reference Probe

Abstract The higher the frequency, the more complex the scattering, diffraction, multiple reflection, and interference that occur in practical applications such as radar-installed vehicles and transmitter-installed mobile modules, etc. Near-field measurement in “real situations” is important for not only investigating the origin of unpredictable field distortions but also maximizing the system performance by optimal placement of antennas, modules, etc. Here, as an alternative to the previous vector-network-analyzer-based measurement, we propose a new asynchronous approach that visualizes the amplitude and phase distributions of electric near-fields three-dimensionally without placing a reference probe at a fixed point or plugging a cable to the RF source to be measured. We demonstrate the visualization of a frequency-modulated continuous wave (FMCW) signal (24 GHz ± 40 MHz, modulation cycle: 2.5 ms), and show that the measured radiation patterns of a standard horn antenna agree well with the simulation results. We also demonstrate a proof-of-concept experiment that imitates a realistic situation of a bumper installed vehicle to show how the bumper alters the radiation patterns of the FMCW radar signal. The technique is based on photonics and enables measuring in the microwave to millimeter-wave range.

scholarly journals Sub-surface melting in a seasonal snow cover

1995 ◽  
Vol 41 (139) ◽  
pp. 474-482 ◽  
Author(s):  
Gary Koh ◽  
Rachel Jordan
Keyword(s):  
Surface Temperature ◽  
Snow Cover ◽  
Continuous Wave ◽  
Surface Melting ◽  
Balance Model ◽  
Fmcw Radar ◽  
Seasonal Snow ◽  
Wet Snow ◽  
Seasonal Snow Cover ◽  
Good Agreement

AbstractThe ability of solar radiation to penetrate into a snow cover combined with the low thermal conductivity of snow can lead to a sub-surface temperature maximum. This elevated sub-surface temperature allows a layer of wet snow to form below the surface even on days when the air temperature remains sub-freezing. A high-resolution frequency-modulated continuous wave (FMCW) radar has been used to detect the onset of sub-surface melting in a seasonal snow cover. The experimental observation of sub-surface melting is shown to be in good agreement with the predictions of a one-dimensional mass- and energy-balance model. The effects of varying snow characteristics and solar extinction parameters on the sub-surface melt characteristics are investigated using model simulations.

scholarly journals Radar Imager for Mars’ Subsurface Experiment—RIMFAX

2020 ◽  
Vol 216 (8) ◽  
Author(s):  
Svein-Erik Hamran ◽  
David A. Paige ◽  
Hans E. F. Amundsen ◽  
Tor Berger ◽  
Sverre Brovoll ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Sand Dunes ◽  
Landing Site ◽  
Wide Band ◽  
Center Frequency ◽  
Depth Range ◽  
Fmcw Radar ◽  
Shallow Subsurface ◽  
Eventual Return ◽  
Ground Penetrating

AbstractThe Radar Imager for Mars’ Subsurface Experiment (RIMFAX) is a Ground Penetrating Radar on the Mars 2020 mission’s Perseverance rover, which is planned to land near a deltaic landform in Jezero crater. RIMFAX will add a new dimension to rover investigations of Mars by providing the capability to image the shallow subsurface beneath the rover. The principal goals of the RIMFAX investigation are to image subsurface structure, and to provide information regarding subsurface composition. Data provided by RIMFAX will aid Perseverance’s mission to explore the ancient habitability of its field area and to select a set of promising geologic samples for analysis, caching, and eventual return to Earth. RIMFAX is a Frequency Modulated Continuous Wave (FMCW) radar, which transmits a signal swept through a range of frequencies, rather than a single wide-band pulse. The operating frequency range of 150–1200 MHz covers the typical frequencies of GPR used in geology. In general, the full bandwidth (with effective center frequency of 675 MHz) will be used for shallow imaging down to several meters, and a reduced bandwidth of the lower frequencies (center frequency 375 MHz) will be used for imaging deeper structures. The majority of data will be collected at regular distance intervals whenever the rover is driving, in each of the deep, shallow, and surface modes. Stationary measurements with extended integration times will improve depth range and SNR at select locations. The RIMFAX instrument consists of an electronic unit housed inside the rover body and an antenna mounted externally at the rear of the rover. Several instrument prototypes have been field tested in different geological settings, including glaciers, permafrost sediments, bioherme mound structures in limestone, and sedimentary features in sand dunes. Numerical modelling has provided a first assessment of RIMFAX’s imaging potential using parameters simulated for the Jezero crater landing site.

Semi-Physical Simulation System for FMCW Radar

2011 ◽  
Vol 135-136 ◽  
pp. 886-892
Author(s):  
Wen Hui Chen ◽  
Xin Xi Meng ◽  
Xiao Min Liu
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Physical Simulation ◽  
Continuous Wave ◽  
Low Cost ◽  
Simulation System ◽  
Radar Signal ◽  
Low Power Consumption ◽  
Fmcw Radar ◽  
Data Process

In order to process and analyze the signal of frequency modulated continuous wave (FMCW) radar, a radar semi-physical simulation(RSPS) system based on STM32F103VE6 chip is designed in this paper. By designing the hardware and software of system, the RSPS system can process the radar signal, detect the target, verify the data process algorithm and display the result on TFT-LCD screen. In addition, the collected data can be uploaded to PC by RS-232 interfaces which improves the reliability, stability and practicability of system. The waveform and spectrum maps are utilized to show the feasibility of RSPS system in analysing FMCW radar signal. Experimental results show that this system has many advantages, such as multifunction, low power consumption and low cost.

Target Range and Velocity Measurement to Reduce False Targets in FMCW Automotive Anti-Collision Radar

2012 ◽  
Vol 253-255 ◽  
pp. 1410-1417 ◽  
Author(s):  
Zhi Gang Li ◽  
Qiong Chan Gu
Keyword(s):  
Computer Simulation ◽  
Theoretical Analysis ◽  
Continuous Wave ◽  
Target Range ◽  
Multiple Targets ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Frequency Modulate ◽  
Inherent Problem ◽  
Simulation Results

For frequency modulate continuous wave radar, it is necessary and difficult to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode t o measure range and velocity of multiple targets. However, the inherent problem of FMCW radar is multiple targets detection. False targets can appearance because of mistaking the combination of these beat frequencies. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. Computer simulation results and theoretical analysis prove that the method is effective and practical for multiple targets detection in intelligence transportation system.

scholarly journals High-Resolution Observations of Insects in the Atmospheric Boundary Layer

2008 ◽  
Vol 25 (12) ◽  
pp. 2176-2187 ◽  
Author(s):  
Robert F. Contreras ◽  
Stephen J. Frasier
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Cross Sections ◽  
Continuous Monitoring ◽  
Rayleigh Scattering ◽  
Continuous Wave ◽  
Time Of Day ◽  
Fmcw Radar ◽  
Radar Cross Sections

Abstract High spatial and temporal resolution S-band radar observations of insects in the atmospheric boundary layer (ABL) are described. The observations were acquired with a frequency-modulated continuous-wave (FMCW) radar during the 2002 International H20 Project (IHOP_2002) held in Oklahoma in the months of May and June 2002. During the observational period the boundary layer was convective with a few periods of rain. Rayleigh scattering from particulate scatterers (i.e., insects) dominates the return; however, Bragg scattering from refractive index turbulence is also significant, especially at the top of the afternoon boundary layer. There is a strong diurnal signal in the insect backscatter: minima in the morning and at dusk and maxima at night and midafternoon. Insect number densities and radar cross sections (RCSs) are calculated. The RCS values range from less than 10−12 m2 to greater than 10−7 m2 and likewise have a strong diurnal signal. These are converted to equivalent reflectivity measurements that would be reported by typical meteorological radars. The majority of reflectivity measurements from particulate scatterers ranges from −30 to −5 dBZ; however, intense point scatterers (>10 dBZ) are occasionally present. The results show that although insects provide useful targets for characterization of the clear-air ABL, the requirements for continuous monitoring of the boundary layer are specific to time of day and range from −20 dBZ in the morning to −10 to −5 dBZ in the afternoon and nocturnal boundary layer (NBL).

scholarly journals Observations of tropical rain with a polarimetric X-band radar: first results from the CHUVA campaign

2012 ◽  
Vol 5 (1) ◽  
pp. 1717-1761
Author(s):  
M. Schneebeli ◽  
J. Sakuragi ◽  
T. Biscaro ◽  
C. F. Angelis ◽  
I. Carvalho da Costa ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Radar Data ◽  
Rain Attenuation ◽  
Fmcw Radar ◽  
X Band ◽  
Rain Drop ◽  
First Results ◽  
Radar Measurements ◽  
Drop Size Distributions ◽  
Set Up

Abstract. A polarimetric X-band radar has been deployed during one month (April 2011) for a field campaign in Fortaleza, Brazil, together with additional sensors like a Ka-band vertically pointing frequency modulated continuous wave (FMCW) radar and three laser disdrometers. The disdrometers as well as the FMCW radar are capable of measuring the rain drop size distributions (DSDs), hence making it possible to forward-model theoretical polarimetric X-band radar observables at the point where the instruments are located. This set-up allows to thoroughly test the accuracy of the X-band radar measurements as well as the algorithms that are used to correct the radar data for radome and rain attenuation. In the first campaign in Fortaleza it was found that radome attenuation dominantly affects the measurements. With an algorithm that is based on the self-consistency of the polarimetric observables, the radome induced reflectivity offset was estimated. Offset corrected measurements were then further corrected for rain attenuation with two different schemes. The performance of the post-processing steps is being analyzed by comparing the data with disdrometer-inferred polarimetric variables that were measured in a distance of 20 km to the radar.

scholarly journals Discrete Human Activity Recognition and Fall Detection by Combining FMCW RADAR Data of Heterogeneous Environments for Independent Assistive Living

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2237
Author(s):  
Umer Saeed ◽  
Syed Yaseen Shah ◽  
Syed Aziz Shah ◽  
Jawad Ahmad ◽  
Abdullah Alhumaidi Alotaibi ◽  
...  
Keyword(s):  
Human Activity ◽  
Human Activities ◽  
Daily Living ◽  
Continuous Wave ◽  
Learning Algorithm ◽  
Confusion Matrix ◽  
Research Work ◽  
Heterogeneous Environments ◽  
Fmcw Radar ◽  
Unseen Data

Human activity monitoring is essential for a variety of applications in many fields, particularly healthcare. The goal of this research work is to develop a system that can effectively detect fall/collapse and classify other discrete daily living activities such as sitting, standing, walking, drinking, and bending. For this paper, a publicly accessible dataset is employed, which is captured at various geographical locations using a 5.8 GHz Frequency-Modulated Continuous-Wave (FMCW) RADAR. A total of ninety-nine participants, including young and elderly individuals, took part in the experimental campaign. During data acquisition, each aforementioned activity was recorded for 5–10 s. Through the obtained data, we generated the micro-doppler signatures using short-time Fourier transform by exploiting MATLAB tools. Subsequently, the micro-doppler signatures are validated, trained, and tested using a state-of-the-art deep learning algorithm called Residual Neural Network or ResNet. The ResNet classifier is developed in Python, which is utilised to classify six distinct human activities in this study. Furthermore, the metrics used to analyse the trained model’s performance are precision, recall, F1-score, classification accuracy, and confusion matrix. To test the resilience of the proposed method, two separate experiments are carried out. The trained ResNet models are put to the test by subject-independent scenarios and unseen data of the above-mentioned human activities at diverse geographical spaces. The experimental results showed that ResNet detected the falling and rest of the daily living human activities with decent accuracy.

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