A Comparison of Ice Freeboard Measurement by Icesat and Envisat Altimeters

Remote sensing plays an essential role in the continuous monitoring of sea ice in polar regions. This study fills the gap in literature by conducting a cross-mission analysis between ICESat and EnviSat from 2005 to 2009. The methodology consists of two parts: 1) Compare ocean surface elevation measurement. 2) Deriving freeboard from ICESat and EnviSat independently. Results show that: 1) There is a strong correlation between ICESat and EnviSat measured surface elevation. 2) Despite the penetration ability of Ku band radar altimeter, EnviSat measured elevation is consistently above ICESat. 3) According to the estimated freeboard, Southern Beaufort Sea is dominated by first year ice.