Infrared imaging of buried objects by thermal step-function excitations.

Sudden heating or cooling of a surface, by turning on or off radiation flux on the surface, is used as a means of enhancing the detection capability of buried objects by thermal infrared imaging. An experimental analysis of a sand-surface temperature is presented as a function of a buried object's composition and depth, and it is compared with theoretical simulations. Object identification by means of the geometry of isothermal contours and the rate of change of the surface temperature with radiant flux is discussed.