Travel Time Computation in Snow and Ice Volumes for Radar Remote Sensing Applications

When radar signals penetrate snow and ice, they experience additional delays and directional changes due to the higher refractive index compared to that of air. These propagation effects should be taken into account accurately when processing, simulating, or geocoding radar data. Travel time computation is straightforward when the refractive index is constant, but it becomes challenging in heterogeneous media. This letter introduces novel methods based on the Eikonal equation and Fermat’s principle for efficiently computing radar signal travel times in heterogeneous snow and ice volumes. These approaches can accommodate nearly arbitrary refractive index distributions, ensuring precise handling of propagation effects in radar remote sensing applications.