Imaging of firn and bubbly ice in coaxial reflected light: a new techniquefor the characterization of these porous media

A new technique for characterizing the structure of firn and bubbly ice is presented. This technique, based on observation of etched (sublimation) sur faces in coaxial reflected light, enables one to see simultaneously the por e network of the firn or. bubbles in the ice and the crystal boundaries. At the same time, the main stages of image processing used to transform the i nitial photographs into clean binary images are described.