Comparison of backpropagation and synthetic aperture imaging algorithms for processing GPR data

The synthetic aperture imaging (SAI) and backpropagation imaging (BPI) algorithms are compared for reconstructing a representation of scattering objects from time-domain ground-penetrating radar data. Synthetic data produced by a FDTD forward solver is used as a basis for the comparison. We assume initially a homogeneous, lossless host medium. The BPI algorithm, which includes waveform diffractions, is shown to result in a better focused image than SAI, with fewer artifacts. The superiority of the BPI algorithm is particularly evident at lower frequencies, where the scattering objects are on the order of the wavelength of the incident field.