Frequency domain wave-oriented data processing of scattering by truncated periodic strip gratings
Guided by a Floquet-modified GTD model developed by us recently for finite periodic and weakly aperiodic wire gratings, we propose and apply space-wavenumber phase space processing algorithms to extract that phenomenology from a numerical data base. A Method of Moments (MOM) reference algorithm is used to compute the frequency domain (FD) scattering data for truncated gratings whose elements are arbitrarily oriented, periodically distributed strips rather than thin wire filaments. Because the processing is tied to the wave physics, we refer to this procedure as wave-oriented data processing. Implementation involves projection onto appropriate FD phase space subdomains, and the generation of space-wavenumber phase-space distributions by windowed Fourier transforms. It is found that this form of FD processing highlights effects of truncation and perturbed periodicity but is less sensitive to the structure of the grating elements (i.e. wires vs. strips). In a companion paper at this meeting, we perform phase space processing in the time domain (TD), show how TD phenomenology is revealed via time-frequency distributions, and show also how short-pulse excitation enhances the sensitivity with respect to element structure.
