The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform

Ioan Nicolaescu - One of the best experts on this subject based on the ideXlab platform.

  • improvement of stepped frequency continuous wave ground penetrating radar cross range Resolution
    IEEE Transactions on Geoscience and Remote Sensing, 2013
    Co-Authors: Ioan Nicolaescu
    Abstract:

    This paper presents some experimental results obtained with newly developed stepped-frequency continuous wave (SFCW) ground-penetrating radar in a frequency range from 400 to 4845 MHz. This paper describes the procedures to remove the delays within the transmitter, the receiver, and the antenna system and analyzes the experimental results obtained after processing the measured data. The measured system footprint and the experimental results show that using an ultrawideband (UWB) Archimedean spiral antenna decreases the coupling signal but does not provide the needed Cross-Range Resolution. Based on the measured dimensions of the footprint, a synthetic aperture procedure is used to improve the radar Cross-Range Resolution from around 60 cm to about 6 cm. This paper shows the ability of the radar to detect dielectric objects and to exhibit their shape as it works with circularly polarized waves. What makes this paper different from prior work, which presents some experiments using a vector network analyzer set up to work as an SFCW radar, is that the data were acquired with a real system working with circular polarization and using two UWB Archimedean spirals. The calibration procedures as well as the synthetic aperture procedure were developed and validated based on measured data with the SFCW radar.

Francesco Soldovieri - One of the best experts on this subject based on the ideXlab platform.

  • forward looking ground penetrating radar via a linear inverse scattering approach
    IEEE Transactions on Geoscience and Remote Sensing, 2015
    Co-Authors: Ilaria Catapano, Antonio Affinito, Alessio Del Moro, Giovanni Alli, Francesco Soldovieri
    Abstract:

    An inverse scattering approach has been designed to process data gathered by means of forward-looking ground-penetrating radar systems. Such an inverse approach exploits a linear model of the scattering phenomenon and is able to account for the half-space 2-D geometry. In this frame, a theoretical study on the achievable reconstruction capabilities is provided with the aim to estimate the range and Cross-Range Resolution limits and gain indications about the issue of how to design the measurement configuration. Finally, numerical and experimental examples are provided to assess the effectiveness of the approach.

Mengdao Xing - One of the best experts on this subject based on the ideXlab platform.

  • achieving higher Resolution isar imaging with limited pulses via compressed sampling
    IEEE Geoscience and Remote Sensing Letters, 2009
    Co-Authors: Lei Zhang, Mengdao Xing, Chengwei Qiu, Zheng Bao
    Abstract:

    Recent theory of compressed sampling (CS) suggests that exact recovery of an unknown sparse signal with overwhelming probability can be achieved from very limited number of samples. In this letter, we adapt this idea and present a framework of high-Resolution inverse synthetic aperture radar imaging with limited measured data. During the framework, we mathematically convert the imaging into a problem of signal reconstruction with orthogonal basis; hence, a conceptive upper bound of the Cross-Range Resolution is presented based on the CS theory. Real data results show that the CS imaging approach outperforms the conventional range-Doppler one in Resolution.

  • new isar imaging algorithm based on modified wigner ville distribution
    Iet Radar Sonar and Navigation, 2009
    Co-Authors: Mengdao Xing, Renbiao Wu, Yongkang Li
    Abstract:

    Inverse synthetic aperture radar (ISAR) imaging of air, space or ship targets with complex motion has attracted the attention of many researchers in the past decade. Complex motion of targets induce Cross-Range scatterer-variant quadratic phase terms, which will degrade the Cross-Range Resolution and affect focusing quality. A new algorithm is proposed for the ISAR imaging of complex moving targets. First, conventional range alignment, phase compensation and range compression are performed over the raw phase history data such that each range bin can be modelled as the sum of several linear frequency modulation or chirp signals. Secondly, a modified-Wigner-Ville distribution (referred to as M-WVD) approach is proposed, which is based on a scale transform in the time-frequency distribution plane and can effectively suppress the troublesome cross-term interference associated with WVD via coherent integration. Finally, the azimuth ISAR image can be obtained via a simple maximisation projection from the two-dimensional accumulated plot to the azimuth dimension. Compared with existing WVD-based ISAR imaging algorithms, the proposed method has the following features: better cross-term interference reduction achieved at no Resolution loss, computationally more efficient with no expensive two-dimensional parameter search, and higher signal processing gain because of coherent integration during the whole imaging time. Both numerical and experimental results are provided to demonstrate the performance of the proposed method.

Ilaria Catapano - One of the best experts on this subject based on the ideXlab platform.

  • forward looking ground penetrating radar via a linear inverse scattering approach
    IEEE Transactions on Geoscience and Remote Sensing, 2015
    Co-Authors: Ilaria Catapano, Antonio Affinito, Alessio Del Moro, Giovanni Alli, Francesco Soldovieri
    Abstract:

    An inverse scattering approach has been designed to process data gathered by means of forward-looking ground-penetrating radar systems. Such an inverse approach exploits a linear model of the scattering phenomenon and is able to account for the half-space 2-D geometry. In this frame, a theoretical study on the achievable reconstruction capabilities is provided with the aim to estimate the range and Cross-Range Resolution limits and gain indications about the issue of how to design the measurement configuration. Finally, numerical and experimental examples are provided to assess the effectiveness of the approach.

B L Douglas - One of the best experts on this subject based on the ideXlab platform.

  • synthetic aperture sonar imaging with a multiple element receiver array
    International Conference on Acoustics Speech and Signal Processing, 1993
    Co-Authors: B L Douglas
    Abstract:

    The application of synthetic aperture techniques in sonar imaging of the ocean floor has been limited by sonar platform instability. The authors present a robust algorithm for motion estimation and compensation to perform synthetic aperture image formation. First, the algorithm uses the acoustic returns from a receiver array to form a complex-valued physical-aperture image for each transmit burst. Perturbations of the sonar platform velocity or attitude manifest themselves as registration errors and phase errors between successive images. The registration errors are estimated by cross-correlation-based techniques, and the images are aligned spatially. The phase errors are then removed. Finally, after phase correction, the registered images are coherently superimposed to form a high-Resolution synthetic aperture sonar image. Results of experiments at sea with a prototype synthetic aperture sonar system are presented. A small point reflector on a sandy bottom at 70 m range was imaged using a 400 wavelength physical aperture and the synthetic aperture technique to compare the performance in detecting small targets near the maximum operating range of the sonar. The synthetic aperture image exhibits superior Cross-Range Resolution and higher signal-to-noise ratio compared with the conventional techniques. >