Development and application of radar reflectometer using micro to infrared waves

Mase, A.; Kogi, Y.; Kuwahara, Daisuke; Nagayama, Y.; Ito, Naoki; Maruyama, Toru; Ikezi, H.; Wang, Xiaolong; Inutake, M.; Tokuzawa, T.; Kohagura, J.; Yoshikawa, Masayuki; Shinohara, Shunjiro; Suzuki, Akihiro; Sakai, F.; Yamashika, M.; Tobias, Benjamin; Muscatello, C. M.; Ren, X.; Chen, M.; Domier, Calvin; Luhmann, Neville C.

doi:10.1080/23746149.2018.1472529

Cited by 12 publications

(10 citation statements)

References 98 publications

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“…Then the values become close to each other. In the previous experiment using a 10 GHz reflectometer system, the value of LF/HF has the similarity within ±30% or more [6,14]. However, the 24 GHz system introduces much more discrepancy.…”

Section: Resultsmentioning

confidence: 86%

“…Two methods (algorithms) have been developed to evaluate instantaneous heartbeat interval (heart rate) [6,13,14]. One is cross-correlation technique.…”

Section: Evaluation Of Hr and Hrvmentioning

confidence: 99%

“…Several methods have been developed such as electrocardiograph (ECG), piezoelectric sensor, ultrasonic sensor, and infrared and microwave reflectometry sensors [1][2][3][4][5]. Microwave reflectometry, especially in larger than 10 GHz region, remotely measures human skin movements when breathing and heartbeat are present [6].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-Contact and Non-Invasive Driver's Monitor Using Microwave Reflectometer

Mase

Kogi

Maruyama

et al. 2020

PIER M

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This paper describes the measurement of a driver's instantaneous heart rate corresponding to R-R interval in electrocardiogram and heart-rate variability (HRV) using 24 GHz radar reflectometers. Elimination of the spurious component due to random movement of a driver has been the most difficult problem for microwave measurement. Auto-gain control of the receiver, template matching and crosscorrelation technique among multiple reflectometers enable motion artifact elimination, signal peak detection, and data processing for various parameters. The measurement of vital signals is considered useful for predicting the change in a driver's state, such as a heart attack as well as detecting drowsy driving, drunk driving, and fatigue.

show abstract

Section: Resultsmentioning

confidence: 86%

“…Two methods (algorithms) have been developed to evaluate instantaneous heartbeat interval (heart rate) [6,13,14]. One is cross-correlation technique.…”

Section: Evaluation Of Hr and Hrvmentioning

confidence: 99%

See 1 more Smart Citation

Non-Contact and Non-Invasive Driver's Monitor Using Microwave Reflectometer

Mase

Kogi

Maruyama

et al. 2020

PIER M

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show abstract

“…The first is the ability to penetrate dielectric materials. The second is the use of sensitive phase fluctuation measurements [13]. In this work, a type of radar reflectometer was first applied for the measurement, which utilizes the phase interference effect of reflected waves due to the multiple reflection between the two layers (Fabry-Perot effect).…”

Section: Introductionmentioning

confidence: 99%

Imaging Diagnostics of Inside of a Building Wall Using Millimeter-Wave Reflectometer

Osaki¹,

Mase

Hirata

et al. 2022

Applied Sciences

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Progress in microwave and millimeter-wave technologies has enabled advanced diagnostics for industrial applications. The transmission, reflection, scattering and radiation processes of electromagnetic waves are utilized as diagnostic principles. Specifically, the reflectometric method has gained importance in various applications due to the possibility of the high localization and accessibility of measurements, as well as the non-destructive nature of the systems. In this paper, radar reflectometers were applied to the measurement of the inside of a building wall, that is, the inspection of tile materials attached to a concrete wall. The measurement principle utilizes the phase interference effect of the reflected wave due to the multiple reflections between the two layers (Fabry–Perot effect). The results show the imaging inside the surface related to the peering condition between the tile and concrete wall, and the quantitative evaluation of the condition with non-destructive inspection.

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“…Reflectometry is known to be a versatile tool able to give access to macroscopic plasma parameters (density profile, plasma velocity, radial electric field) or to density perturbations, which are associ-ated to turbulence [1], MagnetoHydroDynamic activities [2], mode excitations by fast particles [3], and more [4,5]. However, to access all of this information, it is necessary to have interpretative models adapted to the different kinds of microwave systems.…”

Section: Introductionmentioning

confidence: 99%

On frequency-independent horn antenna design for plasma positioning reflectometers, from simulation to prototype testing

Lips¹,

Heuraux²,

Lechte³

et al. 2021

J. Inst.

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Using a new framework for horn antenna optimization, a first frequency-independent horn antenna for a plasma positioning reflectometer (PPR) is designed. This hardware optimization is a new approach aiming on lowering the computational complexity of PPR interpretative models able to extract profiles and fluctuations of electron density and temperature from reflectometry measurements. PPR measurements are a strong candidate to provide real-time feedback for plasma position control in long-discharge fusion tokamaks such as ITER and DEMO, which requires fast interpretative models. Reducing the computational complexity of these models is therefore critical. In this paper, ray tracing simulations in the poloidal plane are used to compare different radiation patterns and evaluate them on multiple performance criteria. An antenna shape leading to a frequency-independent far-field radiation diagram is found with the PROFUSION optimizer and a prototype of this antenna is tested against an unoptimized conical reference antenna. The ray tracing performance criteria indicate that fundamental Gaussian frequency-independent antennas perform well, albeit in general worse than same-sized frequency-dependent antennas. Furthermore, it is seen that the pyramidal ITER gap 6 antenna performs well given the spatial constraints and that more performant antennas could be used, when more space was available. The prototype testing reveals challenges in obtaining frequencyindependent characteristics within a tokamak blanket environment, which is additionally complicated by misalignment risks.

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Development and application of radar reflectometer using micro to infrared waves

Cited by 12 publications

References 98 publications

Non-Contact and Non-Invasive Driver's Monitor Using Microwave Reflectometer

Non-Contact and Non-Invasive Driver's Monitor Using Microwave Reflectometer

Imaging Diagnostics of Inside of a Building Wall Using Millimeter-Wave Reflectometer

On frequency-independent horn antenna design for plasma positioning reflectometers, from simulation to prototype testing

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