UHF Radar Sounding of Polar Ice Sheets

• Published in: IEEE Geoscience and Remote Sensing Letters
• Main Authors: Yan, Jie-Bang, Nunn, Joshua A., Gogineni, Prasad, O'Neill, Charles, Simpson, Christopher D., Taylor, Ryan A., Steinhage, Daniel, Dahl-Jensen, Dorthe, Miller, Heinrich, Eisen, Olaf
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2020
• Subjects: Antarc*; Antarctica; East Greenland; Greenland; Ice Shelf
• Online Access: https://epic.awi.de/id/eprint/50387/; https://hdl.handle.net/10013/epic.baf6b8fc-ab86-440f-9a5f-51e7c55e45a5

In this letter, we report on the design, development, and field operation of a surface-based multi-channel ultraw- ideband (UWB) ultrahigh frequency (UHF) radar to measure ice thickness, basal conditions, and ice-shelf bottom melt rates. The radar concept is based on the recent success in sounding shallow low-loss ice (∼1 km) and measuring the ice-shelf melt rates with a 600–900-MHz low-power radar, referred to as the accumulation radar. Our proposed radar system operates over the same frequency band, from 600 to 900 MHz, with a peak transmit power of 800 W. We used a large and lightweight 16 m × 17 m antenna array arranged in a Mills cross-configuration to obtain the required radar sensitivity to sound more than 3-km- thick ice and image the internal layers at a fine vertical resolution of about 60 cm. We used the system at the East Greenland Ice-coring Project (EGRIP) site in Summer 2018 to collect data over ∼100 km of lines. We sounded about 2.8-km-thick ice with more than 40-dB signal-to-noise ratio and mapped the internal layers to a depth of almost 2.5 km. Our results show that an airborne or spaceborne radar operating at frequencies as high as 900 MHz with a large antenna array can be used to map large ice sheets in Greenland and Antarctica.