Radar wave scattering loss in a densely packed discrete random medium:   Numerical modeling of a box-of-boulders experiment in the Mie regime

doi:10.1016/j.jappgeo.2013.08.022

CORC > 北京大学 > 地球与空间科学学院

	Radar wave scattering loss in a densely packed discrete random medium: Numerical modeling of a box-of-boulders experiment in the Mie regime
	Liu, Lanbo ; Li, Zhanhui ; Arcone, Steven ; Fu, Lei ; Huang, Qinghua
刊名	journal of applied geophysics
	2013
关键词	Discrete random medium model Mie scattering Ground penetrating radar Wave energy loss Numerical modeling DIELECTRICS PULSES
DOI	10.1016/j.jappgeo.2013.08.022
英文摘要	In rough geologic media such as alluvial gravels, glacial tills, talus or colluvium, the grain sizes may span the range of GPR in situ wavelengths. Here we experimentally and numerically modeled the scattering loss from both rough-surface and subsurface dielectric scatterers. The combination of the selected radar frequency and the dimension of the scatterers placed the scattering within the Mie regime. We compared the GPR signal amplitude and waveform reflected from the metal sheet on the bottom of a large box filled with boulders with the numerically computed response from a discrete random medium (DRM) model. The DRM consists of a collection of densely packed ellipsoids. The size and orientation of the ellipsoids are randomized; the size has a Gaussian distribution similar to the physical experiment. The dielectric permittivity of the ellipsoids is constant and their electric conductivity is negligible. The starting in situ dominant pulse wavelength at 900 MHz was about 17 cm, as was about the average rock dimension. Experimentally, the 900-MHz radar pulse underwent most dispersion within the first in situ wavelength of depth, and then, at 500-700 MHz dominant frequency, the pulses underwent a near inverse range dependency loss rate, as if the media were a pure dielectric. The numerical model agrees well with the experimental data. Both experimental and numerical results support a significant scattering loss in Mie regime. Besides the scattering attenuation loss, velocity dispersion has also been observed from both observation and simulation. However, the scattering attenuation and dispersion cannot be fit by the Kramers-Kronig relation that is commonly found in intrinsic attenuation and worth further theoretical investigations. (C) 2013 Elsevier B.V. All rights reserved.; Geosciences, Multidisciplinary; Mining & Mineral Processing; SCI(E); EI; 1; ARTICLE; ,SI; 68-75; 99
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/219081]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Liu, Lanbo,Li, Zhanhui,Arcone, Steven,et al. Radar wave scattering loss in a densely packed discrete random medium: Numerical modeling of a box-of-boulders experiment in the Mie regime[J]. journal of applied geophysics,2013.
APA	Liu, Lanbo,Li, Zhanhui,Arcone, Steven,Fu, Lei,&Huang, Qinghua.(2013).Radar wave scattering loss in a densely packed discrete random medium: Numerical modeling of a box-of-boulders experiment in the Mie regime.journal of applied geophysics.
MLA	Liu, Lanbo,et al."Radar wave scattering loss in a densely packed discrete random medium: Numerical modeling of a box-of-boulders experiment in the Mie regime".journal of applied geophysics (2013).