Subbottom Acoustic Impedance Profiles from Magnitude And Phase Analysis of Echoes

A method for analyzing subbottom echoes is presented using both magnitude and phase analysis. Previous analysis have used only the magnitude of the signal as definitive phase information was not available as the targets insonated were always smaller than the beam size [7], [8]. However, more than half the information is contained in the phase of the signal, which can be obtained from high resolution pencil-point beams. These techniques which have been extensively used in radio and radar sounding of the ionosphere have been applied in this paper in the analysis of sonar sounding of a lake subbottom.