Acoustic-Seismic methods for landmine detection are under intensive investigation. Data collected by the University of Mississippi have by processed by a variety of investigators with excellent results in many cases. Increases in performance are sought based on an understanding of the physical principles leading to the differences between the vibrational velocities of soil over buried landmines and over locations not above landmines. Donskoy suggested modeling the physical system using damped harmonic oscillators. This model suggests a use of magnitude and phase information in image processing algorithms for detecting. In this paper, some methods for incorporating magnitude and phase into image processing algorithms are described and demonstrated. Previous algorithms relied on magnitude only. Increased performance is achieved by incorporating phase into the algorithms.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.