A Novel Range Processing Method of Surface-Based FMCW Ice-Sounding Radar for Accurately Mapping the Internal Reflecting Horizons in Antarctica

Abstract

In this article, we establish the nonlinear signal model of the surface-based frequency-modulated continuous wave ice-sounding radar, and propose a novel range processing strategy that aims at removing the frequency ramp nonlinearity effectively. The proposed algorithm takes full consideration of the dependence of nonlinearity on the round-trip delay time while providing certain robustness of noise. The theory analysis and implementation steps of the proposed algorithm are demonstrated. The full-scale simulations with different kinds of nonlinearities and various signal-to-noise ratios verify the effectiveness and robustness of the proposed algorithm. We also apply the proposed method to real dataset collected during the 31st Chinese Antarctic Research Expedition (CHINARE 31) and CHINARE 33. The result shows the effectiveness of our algorithm on illustrating clarified internal reflecting horizons of ice sheets. Compared with the echograms processed by the typical range processing scheme, our algorithm performs better in nonlinearity elimination.

Keywords

• Frequency-modulated continuous wave (FMCW) ice-sounding radar
• frequency ramp nonlinearity
• nonlinear signal model
• signal-to-noise ratio (SNR)