A low frequency wideband depth sounder for sea ice

Sea ice plays an important role in the Earth climate system. Techniques used in the past to determine sea ice thickness had fundamental limitations in terms of spatial and temporal coverage. We performed extensive simulations using published ice-core data from both polar regions, and our results suggested the use of a UHF radar system (300-1300 MHz) for sounding thin Antarctic sea ice and thin ice in the Arctic and a VHP radar system (50-250 MHz) for sounding thick Arctic sea ice. Based on the simulation results, we designed a prototype radar system that operates on both the frequency ranges. We have successfully used the system to collect data over sea ice at Barrow, Alaska. The experiments show that with our system, we can measure sea ice thickness with less than 20 cm uncertainty in thickness.