Space-Frequency Ultrawideband Time-Reversal Imaging Method as Applied to Subsurface Objects

We present a time-reversal (TR) ultrawideband (UWB) imaging technique based on the utilization of joint spatial and UWB frequency data acquired by limited-aspect antenna arrays. The targets are assumed to be discrete scatterers embedded in homogeneous or random inhomogeneous subsurface media. A singular value decomposition (SVD) is applied to space-frequency multistatic scattering data matrices indexed by sensor location and frequency data. The resulting singular values and vectors are employed to construct time-domain excitation signals for UWB imaging of the embedded scatterer(s) via synthetic backpropagation.