Space-frequency sampling criteria for electromagnetic scattering of a finite object

The sampling criteria in the wavenumber space for generating the spatial impulse response of a finite target is described. A proper choice of canonical confinement for the target in space can greatly reduce the number of samples required to sufficiently characterize the target's spatial impulse response. Though a sampling lattice may be more efficient in the sense of a reduced number of measurement points per unit volume of hyperspace, it may be less effective when digital processing is involved. Specifically, the time-consuming interpolating step is required to put data presented in other types of sampling lattice into the proper type for the computer. Two-dimensional impulse responses reconstructed from cubic sampled data are compared with those using Mensa et al.'s method. The responses obtained also indicate good potential for image reconstruction via the spatial impulse response.