On the feasibility of space-based radar ice sounding of the Antarctic ice sheet at P-band

• Main Authors: Dall, Jørgen, Kusk, Anders, Corr, Hugh, Nick, Walker, Ginestet, Arnaud, Rommen, Björn, Lin, Chung-Chi
• Format: Conference Object
• Language: English
• Published: 2016
• Subjects: Antarctic; The Antarctic; Greenland; Queen Maud Land; Antarc*; Antarctica; Ice Sheet
• Online Access: https://orbit.dtu.dk/en/publications/a3b0de44-0450-417c-99d9-75366d505215; http://lps16.esa.int/page_session185.php#2189p

Space-based radio echo sounding (RES) of the continental ice sheets can potentially offer full coverage, uniform data quality and sampling. Ice sounding radars must operate at low frequencies in order to ensure low attenuation of the signal as it propagates down through the ice and back from base of the ice sheet. Typical frequencies of airborne radar ice sounders are between 60 MHz and 150 MHz. However, the lowest possible frequency for space-based radar ice sounders is 435 MHz. In 2004 the International Telecommunication Union (ITU) radio regulations allocated a 6 MHz band at 435 MHz (P-band) enabling space-based Earth observation radar missions at a frequency that might be applicable for ice sounding. The payload of ESA's Earth Explorer 7 mission, Biomass, is a P-band radar. At P-band the attenuation and scattering properties of the ice sheets are not as well known as they are at the lower frequencies commonly used from aircraft, but in 2005 ESA commissioned development of a P-band polarimetric airborne radar ice sounder (POLARIS) [1], and encouraging results were obtained with data acquired in Greenland. In February 2011 POLARIS data were acquired in Antarctica as part of a close scientific collaboration between seven organizations in Europe and North and South America [2]. The primary objective of this IceGrav campaign was to measure gravity in Queen Maud Land, but a secondary objective was to acquire P-band sounder data, benefitting from the large coverage offered by the Basler DC3 aircraft used. In this study the feasibility of space-based radar ice sounding is assessed. A two-step approach is applied: (1) Key ice sheet parameters are estimated from the airborne POLARIS data acquired in Antarctica. (2) The performance of potential space-based ice sounding radars is simulated based on the estimated ice parameters and system parameters envisioned for a space-based radar. The first step is accomplished by establishing empirical models of the attenuation coefficients and backscatter coefficients for the ...