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Full-Text Articles in Civil and Environmental Engineering
Cross-Well Radar I: Experimental Simulation Of Cross-Well Tomography And Validation, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Cross-Well Radar I: Experimental Simulation Of Cross-Well Tomography And Validation, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Akram N. Alshawabkeh
This paper explains and evaluates the potential and limitations of conducting Cross-Well Radar (CWR) in sandy soils. Implementing the experiment and data collection in the absence of any scattering object, and in the presence of an acrylic plate (a representative of dielectric objects, such as DNAPL (dense non-aqueous phase liquid) pools, etc.), as a contrasting object in a water-saturated soil is also studied. To be able to image the signature of any object, more than one pair of receiving and transmitting antennas are required. The paper describes a method to achieve repeatable, reliable, and reproducible laboratory results for different transmitter-receiver …
Experimental Validation Of A Numerical Forward Model For Tunnel Detection Using Cross-Borehole Radar, Arvin Farid, Jose A. Martinez-Lorenzo, Akram N. Alshawabkeh, Carey M. Rappaport
Experimental Validation Of A Numerical Forward Model For Tunnel Detection Using Cross-Borehole Radar, Arvin Farid, Jose A. Martinez-Lorenzo, Akram N. Alshawabkeh, Carey M. Rappaport
Akram N. Alshawabkeh
The goal of this research is to develop an experimentally validated twodimensional (2D) finite difference frequency domain (FDFD) numerical forward model to study the potential of radar-based tunnel detection. Tunnel detection has become a subject of interest to the nation due to the use of tunnels by illegal immigrants, smugglers, prisoners, assailants, and terrorists. These concerns call for research to nondestructively detect, localize, and monitor tunnels. Nondestructive detection requires robust image reconstruction and inverse models, which in turn need robust forward models. Cross-Well Radar (CWR) modality is used for experimentation to avoid soil-air interface roughness. CWR is not a versatile …
Cross-Well Radar Ii: Comparison And Experimental Validation Of Modeling Channel Transfer Function, Arvin Farid, Sophia H. Zhan, Akram N. Alshawabkeh, Carey M. Rappaport
Cross-Well Radar Ii: Comparison And Experimental Validation Of Modeling Channel Transfer Function, Arvin Farid, Sophia H. Zhan, Akram N. Alshawabkeh, Carey M. Rappaport
Akram N. Alshawabkeh
Close agreement between theory and experiment is critical for adequate understanding and implementation of the Cross-Well Radar (CWR, otherwise known as Cross-Borehole Ground Penetrating Radar) technique, mentioned in a previous paper by the authors. Comparison of experimental results to simulation using a half-space dyadic Green’s function in the frequency domain requires development of transfer functions to transform the experimental data into a compatible form. A Channel Transfer Function (CTF) was developed to avoid having to model the transmitting and receiving characteristics of the antennas. The CTF considers electromagnetic (EM) wave propagation through the intervening media only (soil in this case), …
Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Akram N. Alshawabkeh
Soil is a complex, potentially heterogeneous, lossy, and dispersive medium. Modeling the propagation and scattering of electromagnetic (EM) waves in soil is, hence, more challenging than in air or in other less complex media. This chapter will explain fundamentals of the numerical modeling of EM wave propagation and scattering in soil through solving Maxwell’s equations using a finite difference time domain (FDTD) method. The chapter will explain how: (i) the lossy and dispersive soil medium (in both dry and fully water-saturated conditions), (ii) a fourth phase (anomaly), (iii) two different types of transmitting antennae (a monopole and a dipole), and …
Tunnel Detection Using Cross Borehole Radar, Clay Kurison, Arvin M. Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Tunnel Detection Using Cross Borehole Radar, Clay Kurison, Arvin M. Farid, Akram N. Alshawabkeh, Carey M. Rappaport
Akram N. Alshawabkeh
Shallow tunnels present both military and homeland security threats. Smugglers with intentions of avoiding border security have turned tunnels into transit routes for trafficking weapons, people, drugs and other illegal materials. Shallow tunnels are also used by prisoners to escape prisons. While drug and human trafficking have long been border concerns, the threat of international terrorism has transformed the effort to detect tunnels into a national security priority. Imminent threats include assailants entering military fortifications by burrowing under buildings, detonation of high grade explosives from foundations of high security facilities, and high level prisoners escaping detention centers through tunnels. Real-time …