An efficient algorithm for time delay estimation

A simple yet effective algorithm called Weighted Fourier transform and RELAXation (WRELAX) is developed to solve a time delay estimation problem. This approach simplifies a complicated nonlinear least squares criterion using relaxation techniques. It utilizes an ultra-wideband ground-penetrating radar to identify and classify roadway subsurface defects. Experimental and numerical examples on the performance of the algorithm are presented.