Applications to Real Measured Data - Introduction to Imaging from Scattered Fields - page 134

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Figure 9.21 FoamMetExt at 6 GHz: (a) Target, (b) Born reconstruction, and (c) cepstral reconstruction.

9.2.4 FoamMetext
FoamMetExt is a hybrid target which contains a large dielectric cylinder with
relative permittivity of ε r ≈ 1.45 and an external metallic cylinder. For metal
objects, the incident scattered field is scattered at the surface and then reflects
back without entering into the object itself. However, due to the scattered field
components, which cross a metal-dielectric interface, the multiple scatter-
ing effects become significant Figure 9.21 shows the reconstruction attempt
of the hybrid object using recently discussed techniques. It is evident from
the figure that the shape of metal objects can be recovered with good qual-
ity even using linear approximations. The Born reconstruction has retrieved
reasonably developed shapes for both the outer metal cylinder and the inner
dielectric cylinder. Figure 9.21c shows that the cepstral reconstruction has
further cleaned the artifacts from the Born reconstruction, but at the expense
of losing valid information about the actual dimension of the shapes.

9.3 CoMpARISon oF ReConStRuCtIon MethodS
In this section, a comparison of reconstructions from various other meth-
ods, some discussed in Chapter 7, that were published in the journal Inverse
Problems volume 21, issue 6, 2005 is presented, compared and discussed here.
These results will also be compared to some of the results from methods pre-
sented in this text.