Anisotropy

We have wriiten some code to calculate the electromagnetic reflection response of an anisotropic layered medium to incident plane wave. In particular, we are interested in the type of signal that might be produced by diaelectric anisotropy due to lattice-preferred orientation of the ice (or alligned gas bubbles or cracks, etc.). We have added a rock bottom to the Vostok model and assumend that it consists of ice with the same % birefringence in the radar band as occur optically (perfectly alligned, hexagonal, 0.3% birefringence). The results indicates that a "split" return can be observed on an receiving antenna that is rotated 90% from the transmitting antenna:

The anisotropic axes are aligned parallel to (x,y,z), with z being vertical. The incident radiation has an electric polarization in the horizontal plane, 45 degrees from x. Electric field observed on two receiving antennas are shown, one parallel to the transmitting antenna, the other perpendicular to it. Because the ice is anisotropic, the perpendicular timeseries is non-zero, and has a two-sided bottom reflection.