Comparison of CryoSat-2 and ENVISAT radar freeboard over Arctic sea ice: toward an improved Envisat freeboard retrieval

摘要: Abstract. Over the past decade, sea-ice freeboard has been monitored with various satellite altimetric missions aim of producing long-term time series ice thickness. While recent studies have demonstrated capacity CryoSat-2 mission (2010–present) to provide accurate measurements, current estimates obtained Envisat (2002–2012) still require some large improvements. In this study, we first estimate and radar by using exact same processing algorithms. We then analyse difference between two over common winter periods (November 2010–April 2011 November 2011–March 2012). The analysis along-track data gridded in conjunction pulse-peakiness (PP) maps suggests that discrepancy sensors is related surface properties floes use a threshold retracker. Based on relation pulse peakiness CryoSat-2, produce monthly CryoSat-2-like version freeboard. improved set displays similar spatial distribution (RMSD  =  1.5 cm) during growth seasons for all months period study. comparison sets situ draught measurements flight shows (RMSE  =  12–28 cm) as (RMSE  =  15–21 cm) much more than uncorrected (RMSE  =  178–179 cm). extended rest demonstrate validity PP correction from calibration period. good agreement (RMSE  =  13–32 cm) demonstrates potential entire lifetime.