Advanced Cepstral Filtering - Introduction to Imaging from Scattered Fields - page 161

table 10.9 A Comparison of Reconstructed Images for a Square Target with Sides
of 2λ Using the Method of Processing Each Source Separately and Then Combining
Them in Cepstrum Space after Filtering for Three Different Permittivity 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 ).

The issue becomes critical as the spacing between the receivers equals or
exceeds the wavelength of the incident field It was also mentioned in Chapter
6 that the use of random spacing for the receivers as they are reduced in num-
ber can be very effective in dealing with this aliasing (Lustig et al., 2007)
and provides a means to reduce the number of receivers needed to effectively
sample the source (Candes and Romber, 2005; Candes and Wakin, 2008).