Radar Echoes

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Hervé Aubert - One of the best experts on this subject based on the ideXlab platform.

  • classification of Radar Echoes for identification and remote reading of chipless millimeter wave sensors
    IEEE Transactions on Microwave Theory and Techniques, 2021
    Co-Authors: Dominique Henry, Timothée Marchal, J Philippe, P Pons, Hervé Aubert
    Abstract:

    This article describes the wireless and simultaneous interrogation and identification of multiple passive (zero-power) pressure sensors in an industrial environment with a reading range of at least 4 m. The 3-D beamscanning of the scene is performed from a 24-GHz frequency-modulated continuous-wave (FM-CW) Radar and for diverse electric field polarizations. The identification is performed using a k-nearest neighbor classification. The benefit of using the cross-polarized electric fields combined with a Radar imagery technique is enlightened from the analysis of the background clutter and the simultaneous remote interrogation of several passive pressure sensors at a distance up to 17.7 m. The measurement uncertainty on pressure obtained from the proposed long-range wireless technique is finally reported and discussed.

  • identification of chipless sensors in cluttered environments from 3d Radar imagery and polarimetry
    URSI General Assembly and Scientific Symposium, 2020
    Co-Authors: Dominique Henry, Timothée Marchal, Julien Philippe, Patrick Pons, Hervé Aubert
    Abstract:

    This paper reports a new method for the identification of chipless sensors based on 3D Radar imagery and polarimetry. Chipless pressure sensors are wirelessly interrogated in a highly reflective environment with a 24GHz FM-CW Radar. A novel algorithm of identification based on the 3D distribution of Radar Echoes is proposed and applied to mitigate the clutter and identify multiple chipless pressure sensors. The electromagnetic footprint of each sensor is defined and advantageously used for identification purposes.

  • proximal Radar sensors for precision viticulture
    IEEE Transactions on Geoscience and Remote Sensing, 2019
    Co-Authors: Dominique Henry, Hervé Aubert, Thierry Veronese
    Abstract:

    In this paper, we report the accurate estimation of vine grape yield from a 3-D Radar imagery technique. Three ground-based frequency-modulated continuous-wave Radars operating, respectively, at 24, 77, and 122 GHz are used for the contact-less estimation of grape mass in vineyards. The 3-D Radar images are built from the beam scanning of the vine plants and allow estimating the mass of grapes from the computation of appropriate statistical estimators. These estimators are derived from the measured polarization and magnitude of Radar Echoes. It is shown that the estimation of grape mass from the proposed ground-based Radar imagery technique at millimeter-wave frequency range may be accurate within 1%.

  • long range wireless interrogation of passive humidity sensors using van atta cross polarization effect and different beam scanning techniques
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Dominique Henry, Hervé Aubert, P Pons, Jimmy Hester, Manos M Tentzeris
    Abstract:

    This paper presents a method for the remote interrogation of batteryless humidity sensors based on statistical estimations and 3-D beam scanning techniques. As a proof-of-concept demonstration, a Van-Atta reflectarray sensor is interrogated with a 24-GHz frequency-modulated continuous-wave transceiver at various reading ranges. The extension of the proposed approach to passive or moving sensors is reported, and the measurement results are discussed. The relative humidity (RH) is derived from the statistical analysis of multidimensional Radar Echoes, while method is proposed to detect the sensor among clutter without knowing its exact position. Moreover, it is demonstrated that the cross-polarization effect of the Van-Atta reflectarray combined with the 3-D beam scanning technique allows the indoor measurement of the RH up to 58 m.

Dominique Henry - One of the best experts on this subject based on the ideXlab platform.

  • classification of Radar Echoes for identification and remote reading of chipless millimeter wave sensors
    IEEE Transactions on Microwave Theory and Techniques, 2021
    Co-Authors: Dominique Henry, Timothée Marchal, J Philippe, P Pons, Hervé Aubert
    Abstract:

    This article describes the wireless and simultaneous interrogation and identification of multiple passive (zero-power) pressure sensors in an industrial environment with a reading range of at least 4 m. The 3-D beamscanning of the scene is performed from a 24-GHz frequency-modulated continuous-wave (FM-CW) Radar and for diverse electric field polarizations. The identification is performed using a k-nearest neighbor classification. The benefit of using the cross-polarized electric fields combined with a Radar imagery technique is enlightened from the analysis of the background clutter and the simultaneous remote interrogation of several passive pressure sensors at a distance up to 17.7 m. The measurement uncertainty on pressure obtained from the proposed long-range wireless technique is finally reported and discussed.

  • identification of chipless sensors in cluttered environments from 3d Radar imagery and polarimetry
    URSI General Assembly and Scientific Symposium, 2020
    Co-Authors: Dominique Henry, Timothée Marchal, Julien Philippe, Patrick Pons, Hervé Aubert
    Abstract:

    This paper reports a new method for the identification of chipless sensors based on 3D Radar imagery and polarimetry. Chipless pressure sensors are wirelessly interrogated in a highly reflective environment with a 24GHz FM-CW Radar. A novel algorithm of identification based on the 3D distribution of Radar Echoes is proposed and applied to mitigate the clutter and identify multiple chipless pressure sensors. The electromagnetic footprint of each sensor is defined and advantageously used for identification purposes.

  • proximal Radar sensors for precision viticulture
    IEEE Transactions on Geoscience and Remote Sensing, 2019
    Co-Authors: Dominique Henry, Hervé Aubert, Thierry Veronese
    Abstract:

    In this paper, we report the accurate estimation of vine grape yield from a 3-D Radar imagery technique. Three ground-based frequency-modulated continuous-wave Radars operating, respectively, at 24, 77, and 122 GHz are used for the contact-less estimation of grape mass in vineyards. The 3-D Radar images are built from the beam scanning of the vine plants and allow estimating the mass of grapes from the computation of appropriate statistical estimators. These estimators are derived from the measured polarization and magnitude of Radar Echoes. It is shown that the estimation of grape mass from the proposed ground-based Radar imagery technique at millimeter-wave frequency range may be accurate within 1%.

  • long range wireless interrogation of passive humidity sensors using van atta cross polarization effect and different beam scanning techniques
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Dominique Henry, Hervé Aubert, P Pons, Jimmy Hester, Manos M Tentzeris
    Abstract:

    This paper presents a method for the remote interrogation of batteryless humidity sensors based on statistical estimations and 3-D beam scanning techniques. As a proof-of-concept demonstration, a Van-Atta reflectarray sensor is interrogated with a 24-GHz frequency-modulated continuous-wave transceiver at various reading ranges. The extension of the proposed approach to passive or moving sensors is reported, and the measurement results are discussed. The relative humidity (RH) is derived from the statistical analysis of multidimensional Radar Echoes, while method is proposed to detect the sensor among clutter without knowing its exact position. Moreover, it is demonstrated that the cross-polarization effect of the Van-Atta reflectarray combined with the 3-D beam scanning technique allows the indoor measurement of the RH up to 58 m.

T Oguchi - One of the best experts on this subject based on the ideXlab platform.

  • multiple scattering formulation of pulsed beam waves in hydrometeors and its application to millimeter wave weather Radar
    IEEE Geoscience and Remote Sensing Letters, 2007
    Co-Authors: S Ito, S Kobayashi, T Oguchi
    Abstract:

    This letter deals with the backscattering of millimeter pulsed beam waves from hydrometeors. A new approach is presented for a solution of time-dependent three-dimensional vector radiative transfer equation for the Stokes vectors to study the multiple-scattering effects of beam waves on Radar Echoes. General solutions for beam waves are derived in an integral form without any approximation. They are given in numerically tractable forms representing the scattering process in the space and time domain. Time-dependent second-order solutions for Radar Echoes of pulsed beam waves are straightforwardly obtained to predict multiple-scattering effects depending on the variation of an incident beam size. It is shown that the inhomogeneity of the radial direction of beam waves causes the mode coupling of waves between the azimuth directions in the scattering matrix, and that the mode coupling depends on the ratio of the incident beam size to the total mean free path length of the medium

  • a new approach to backscattering of pulsed beam waves from hydrometers
    International Geoscience and Remote Sensing Symposium, 2006
    Co-Authors: S Ito, S Kobayashi, T Oguchi
    Abstract:

    This paper deals with the backscattering of millimeter pulsed beam waves from hydrometeors. A new approach is presented for a solution of the time-dependent three dimensional vector radiative transfer equation for the Stokes vectors to discuss the multiple scattering effects of beam waves on Radar Echoes. General solutions including multiple scattering for beam waves are then derived explicitly in an integral form without any approximation. Time dependent second-order solutions for the Radar Echoes of pulsed beam waves are obtained to predict the multiple scattering effects depending on the variation in an incident beam size. It is shown that the inhomogeneity of the radial direction of beam waves causes the mode coupling of waves between the azimuth directions in the scattering matrix and that the mode coupling depends on the ratio of the incident beam size to the mean free path length of the medium.

Zheng Bao - One of the best experts on this subject based on the ideXlab platform.

  • high resolution three dimensional imaging of space targets in micromotion
    IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2015
    Co-Authors: Xueru Bai, Feng Zhou, Zheng Bao
    Abstract:

    High-resolution three-dimensional (3-D) Radar imaging of space targets in micromotion plays a significant role in space target recognition and space situation awareness; thus, it has attracted extensive attention in recent years. Because of the fast rotation, some scattering centers are occluded by others, i.e., the scattering centers cannot be continuously illuminated by Radar in the imaging interval, and their Radar Echoes are discontinuous. In this paper, a nonparametric 3-D imaging method based on scattering center trajectory association is proposed. It deals with target occlusion using the Riemannian manifold optimization and obtains focused imaging of targets in complex micromotion. The effectiveness of the proposed method is validated using simulated data.

  • imaging of micromotion targets with rotating parts based on empirical mode decomposition
    IEEE Transactions on Geoscience and Remote Sensing, 2008
    Co-Authors: Xueru Bai, Feng Zhou, Mengdao Xing, Zheng Bao
    Abstract:

    For micromotion targets with rotating parts, the inverse synthetic-aperture-Radar image of the main body may be shadowed by the micro-Doppler. To solve this problem, this paper proposes an imaging algorithm based on the complex-valued empirical-mode decomposition. First, the Radar Echoes are decomposed into a series of complex-valued intrinsic-mode functions (IMFs). Then, the IMFs from the rotating parts and those from the main body are separated according to the characteristics of their zero-crossings. Finally, the well-focused imaging of the main body via traditional imaging algorithm and the accurate parameter estimation of the rotating part can be obtained. Both the imaging results for the simulated and measured data are given to verify the validity of the proposed algorithm.

Charles A Knigh - One of the best experts on this subject based on the ideXlab platform.

  • the role of giant and ultragiant nuclei in the formation of early Radar Echoes in warm cumulus clouds
    Journal of the Atmospheric Sciences, 2003
    Co-Authors: Ala M Lyth, Sonia Lashertrapp, William A Coope, Charles A Knigh, J Latham
    Abstract:

    Abstract Observations of the formation of the first Radar Echoes in small cumulus clouds are compared with results of a stochastic coalescence model run in the framework of a closed parcel. The observations were made with an instrumented aircraft and a high-powered dual-wavelength Radar during the Small Cumulus Microphysics Study (SCMS) in Florida. The principal conclusion is that coalescence growth on giant and ultragiant nuclei may be sufficient to explain observations. The concentration of cloud droplets varied from under 300 cm−3 when surface winds were from the ocean, to over 1000 cm−3 when the wind direction was from the mainland. Although there is a slight tendency for the altitude of the first 0-dBZ echo to be lower on average in maritime than in continental clouds there were several cases where it was higher. The model results suggest that the lack of correlation is consistent with drops forming on giant and ultragiant nuclei. The first 0-dBZ echo was observed to form at higher altitudes in cloud...

  • first Radar Echoes from cumulus clouds
    Bulletin of the American Meteorological Society, 1993
    Co-Authors: Charles A Knigh, L J Mille
    Abstract:

    Abstract In attempting to use centimeter-wavelength Radars to investigate the early stage of precipitation formation in clouds, “mantle Echoes” are rediscovered and shown to come mostly from scattering by small-scale variations in refractive index, a Bragg kind of scattering mechanism. This limits the usefulness of single-wavelength Radar for studies of hydrometeor growth, according to data on summer cumulus clouds in North Dakota, Hawaii, and Florida, to values of reflectivity factor above about 10 dBZe with 10-cm Radar, 0 dBZe with 5-cm Radar, and −10 dBZe with 3-cm Radar. These are limits at or above which the backscattered Radar signal from the kinds of clouds observed can be assumed to be almost entirely from hydrometeors or (rarely) other particulate material such as insects. Dual-wave-length Radar data can provide the desired information about hydrometeors at very low reflectivity levels if assumptions can be made about the inhomogeneities responsible for the Bragg scattering. The Bragg scattering ...