Reflection profiling of Arctic lake ice using microwave FM-CW radar

摘要

X- and C-band FM-CW radar reflection profiles were obtained across frozen lakes in northern Alaska using a single elevated high-gain antenna. Clear returns were obtained from the air/snow, snow/ice, ice/water, and ice/ground interfaces. Surface-to-bottom signal intensity ratios are within ranges predicted by plane wave reflection theory, use of which also gives plausible permittivity values for the ice-rich bottom silts. Scattering losses are interpreted for the X-band ice-bottom signals, but evidence of increased volumetric scattering loss with increasing ice thickness may have been masked by changes in bottom dielectric contrasts. The results suggest that this type of radar is superior to conventional transient GPR systems for this application and ice grounded to almost any type of bottom sediments could be profiled from an airborne platform. Such a system could help inventory wetland water volume in northern regions.