1,721,033 research outputs found
"Information content of the Born field scattered by an embedded slab: multifrequency, multiview, and multifrequency-multiview cases"
No full text
Innovative possibilities in time domain reflectrometry
No full textIn this contribution we describe new possibilities regarding TDR measurements, related to the measurement of the electromagnetic characteristics of lossy and possibly magnetic and dispersive materials. The proposed advancement is related to the introduction of a spatial diversity in TDR measurements, achievable by means of extensible probes or alternatively by means of arrays of probes. The spatial diversity can replace the frequency diversity increasing the information achievable at single frequency, so allowing measurements immune from the effects of a possibly unknown dispersion law. Moreover, measuring the reflection coefficient at fixed frequency we can achieve information about both the propagation velocity of the electromagnetic wave along the line and about the intrinsic impedance of the line, which in its turn allows to discriminate between the dielectric permittivity and the magnetic permeability of the material, meant as complex quantities in order to include lossy cases too. There are several possible fields of application and in particular, with regard to the properties of the soil (of interest for archaeological prospecting), the attenuation of the waves in the soil can be estimated (which is important in relation with GPR prospecting), or the water content or in some cases the possible presence of some pollutant
Some examples of GPR prospecting for monitoring of the monumental heritage
No full textIn this paper three case histories of ground penetrating radar (GPR) for the monitoring of historical buildings are presented. They aim to present the specific valence of the GPR in the field of the diagnostic of historical buildings, which is a promising field of research, due to the increasing awareness of the relevance (even economic) of the cultural heritage. The presented GPR prospecting cases have been performed on three different constructive elements typical of historical buildings (a wall, a masonry pillar and a marble column) in order to be the answer to different problems such as the characterization of the masonry, the detection of cracks and the imaging of metallic reinforcement bars
GPR Prospecting at the Castle of Alceste in San Vito dei Normanni (Brindisi, Italy)
Full text linkIn this contribution we will show the results of a non-invasive GPR prospecting performed in the archaeological site of San Vito dei Normanni, in the outskirts of Brindisi, Apulia region, southern Italy, where the ancient population of the Messapians had an important settlement. The present work was performed in the framework of a school in the field financed by the Basilicata Region. The interpretation of the data has been based on the depth slices, on the processed Bscans and on the a-priori available information is provided. Future excavations will be driven also by the results achieved from this GPR prospecting
A microwave tomographic imaging approach for multi-bistatic configuration: the choice of the frequency step
No full textThis paper deals with the application of a frequencydomain
microwave-tomography-imaging algorithm to a multibistatic
configuration in ground-penetrating-radar applications.
First, the authors formulate the inverse problem as a linear one
by exploiting the Born approximation. Then, the reconstruction
capabilities of the solution algorithm are investigated, and an
optimal frequency step to be adopted for the reconstruction is
discussed and determined. Finally, inversion results are presented
with synthetic data obtained from time-domain simulations and
then Fourier transformed in frequency domain
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