A method to determine the locations of three dimensional objects busied in a half space medium is presented. The method is based on the reconstruction of a surface impedance function defined by the co-polarized tangential components of electric and magnetic fields via remote field measurements of scattered field. In the presence of 3-D objects, surface impedance becomes a two dimensional function of location and the locations of the peaks of this function indicates the position of buried objects. The scattered field distribution and its derivative on the half space boundary which are required for determination of surface impedance function are obtained through a continuation method of the measured data to the interface. Numerical simulations show that unless the objects are very close, the surface impedance is highly effective in locating the buried objects and also carries information about relative depth, size or material properties of the objects.