Subsurface microwave imaging for nondestructive evaluation of civil structures

A computationally efficient frequency-domain reconstruction algorithm for subsurface microwave imaging is presented. The processing algorithm is based on the generalized wave propagation model, which can be adapted to various data acquisition configurations, source signals, and propagation media. The algorithm is capable of high-resolution imaging of subsurface features in a dispersive medium, and is therefore ideally suited for evaluating the condition of civil structures. Experimental results are presented to demonstrate the resolving capabilities of the technique. A simulation was performed in which a single scatterer was positioned at various depths within a concrete specimen, and the reconstructed images were evaluated for range and azimuthal resolution.<>