A new technique for the detection and height estimation of buried metallic objects is developed. This technique is bused on the phase characteristics of both transmitted and received signals. A discrete Fourier transform via a fast Fourier transform algorithm is used to compute the phase characteristic. The height of the buried metallic object is estimated by detecting the transition frequency and measuring the phase difference between the transition frequency and the next frequency component in the spectrum of the received signal. Computer simulation studies show that this technique is efficient, reliable, and provides sufficient accuracy.