Abstract

This work shows the design of a radar instrument specifically developed for cold ice measurements in polar regions. The instrument is based on a high-performance software-defined radio (SDR) platform, employing sampling frequencies of 800 MHz for digitizing and 1600 MHz for arbitrary signal generation. A flexible multifrequency radar instrument is built on this SDR system, that comprises: 1) a deep ice chirp-pulsed radar working at central frequency of 155 MHz, with 20 MHz of bandwidth, 1 kW of maximum transmitting power and including synthetic aperture radar in post-processing; and 2) a high-resolution shallow-ice frequency-modulated continuous wave radar, which operates from 200–700 MHz and with 100 mW of output power. We used this instrument in December 2017 during a ~460 km over-snow campaign conducted to Subglacial Lake CECs (79°15′ S 87°34′ W), West Antarctica. We measured a maximum ice thickness of ~2700 m using the deep ice radar and ~150 m of snow/firn thickness obtained in high detail by the shallow ice radar. A detailed description of the radar instrument will be presented, together with some results and their comparisons with data previously obtained in the same area with different radar systems. The instrument presented here shows an improvement in signal-to-noise ratio and along-track resolution of bedrock and englacial structures over previous radar measurements, and also the system provides better adaptability for future parameter changes or upgrades.