Parametric study of the scattered electromagnetic field by differently-shaped buried objects in various scenarios
In this study the electromagnetic field scattered by a buried object is obtained by use of a commercial full-wave
frequency-domain solver which implements the Finite Element Method (FEM). The buried object is supposed
to have different simple shapes and material composition such as a cylinder or cylindrical shell modelling for
example a void in concrete or a poly-vinyl chloride (PVC) pipeline, respectively. Material properties available in
literature are correctly modelled by data interpolation. The model is excited by a linearly-polarized plane wave
impinging normally on the interface between air and soil/cement half-space. Comparison with simulation data
provided by another simulator implementing the finite-difference time domain (FDTD) technique in the case of
a simple buried perfect electric cylinder allows for FEM data validation. We further study the properties and the
spatial variation of the scattered fields in different contexts by varying the geometrical and material properties
of the model relative to the impinging wave characteristics. The aim is to clearly determine the conditions under
which detection is possible. Moreover, by application of signal processing techniques to scattered field data, the
position, shape, and object orientation recognition problems are considered. Results from different DSP algorithms
are compared with the goal to find the best performing one relative to the context. Performance is evaluated in
terms of detection success and resolving ability. The use of ground penetrating radar (GPR) techniques in the field
of Civil Engineering offers inspection capabilities in the structure with no destructive intervention.