Advanced Cepstral Filtering - Introduction to Imaging from Scattered Fields - page 162

table 10.10 A Comparison of Reconstructed Images for Square Targets with Sides of
2λ in Length Using the Method of Processing Each Source Separately and Then
Combining Them in Cepstrum Space after Filtering, Repeated for Three Different
Perm ittivity Values
Reconstructed image Processing each source separately and combining in the
cepstrum Domain

ε r no subtraction subtracting Ψ inc

1.1

1.5

1.9

Note: These images compare the results of subtracting the cepstrum version of the incident ( Ψ inc ).

For the model setup for the sample code in this text, the receiver spacing
from the center of the target area is 760 mm. It was observed at the output of
the cepstrum filtering method earlier that aliasing started to appear once the
number of receivers dropped below 90 for an incident frequency of 5 GHz.
The wavelength of the incident frequency of 5 GHz is 60 mm. In general, the
spacing between equispaced receivers in 2-D is calculated by dividing the
circumference by the number of the receivers: