scholarly journals EM Modelling of Monostatic RCS for Different Complex Targets in the Near-Field Range: Experimental Evaluation for Traffic Applications

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1890 ◽  
Author(s):  
Pablo Sanchez-Olivares ◽  
Lorena Lozano ◽  
Álvaro Somolinos ◽  
Felipe Cátedra

An evaluation of monostatic radar cross section (RCS) response in the near-field range was performed for several targets with different and complex topologies. The main objective was to provide and validate an efficient tool based on electromagnetic (EM) simulations to characterize a traffic scenario. Thus, a novel method based on the combination of geometrical theory of diffraction (GTD) and physical optics (PO) was used to estimate RCS, and the results were compared with the method of moments (MoM) methodology. The simulations were experimentally validated using a commercial vehicular frequency-modulated continuous wave (FMCW) radar at 24 GHz. With this simple measurement system, RCS measurements can be made using an easier and cheaper process to obtain RCS response in the near-field range, which is the most usual situation for traffic applications. A reasonable agreement between the measurements and the EM simulations was observed, validating the proposed methodology in order to efficiently characterize the RCS of targets typically found in real traffic scenarios.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shintaro Hisatake ◽  
Junpei Kamada ◽  
Yuya Asano ◽  
Hirohisa Uchida ◽  
Makoto Tojo ◽  
...  

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.


Author(s):  
Jeff Dunnihoo ◽  
Pasi Tamminen ◽  
Toni Viheriäkoski

Abstract In this study we present a novel method to use a field collapse method together with fully automated near field scanning equipment to construct E- and H-field information of a system during transient ESD events. This inexpensive method provides an alternative way for system designers to validate and analyze the EMC/ESD capability of electronic systems without TLP pulsers, ESD simulators, or precision inductive current probes.


2021 ◽  
pp. 1-12
Author(s):  
Lauro Reyes-Cocoletzi ◽  
Ivan Olmos-Pineda ◽  
J. Arturo Olvera-Lopez

The cornerstone to achieve the development of autonomous ground driving with the lowest possible risk of collision in real traffic environments is the movement estimation obstacle. Predicting trajectories of multiple obstacles in dynamic traffic scenarios is a major challenge, especially when different types of obstacles such as vehicles and pedestrians are involved. According to the issues mentioned, in this work a novel method based on Bayesian dynamic networks is proposed to infer the paths of interest objects (IO). Environmental information is obtained through stereo video, the direction vectors of multiple obstacles are computed and the trajectories with the highest probability of occurrence and the possibility of collision are highlighted. The proposed approach was evaluated using test environments considering different road layouts and multiple obstacles in real-world traffic scenarios. A comparison of the results obtained against the ground truth of the paths taken by each detected IO is performed. According to experimental results, the proposed method obtains a prediction rate of 75% for the change of direction taking into consideration the risk of collision. The importance of the proposal is that it does not obviate the risk of collision in contrast with related work.


Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 452
Author(s):  
Alexey Noskov ◽  
Sebastian Achilles ◽  
Jörg Bendix

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.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6443
Author(s):  
Jinmoo Heo ◽  
Yongchul Jung ◽  
Seongjoo Lee ◽  
Yunho Jung

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.


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