Cryosat-2 Altimeter Performance Assessment Over Ocean.
Ollivier, Annabelle1; Labroue, Sylvie1; Guibbaud, Marielle1; Picot, Nicolas2; Femenias, Pierre3; Parrinello, Tommaso3; Bouzinac, Catherine3

Cryosat -2 mission is dedicated to Cryosphere sciences. Nevertheless, it has, in theory, the potential to be a mission of opportunity for oceanography. Indeed, the satellite embarks an innovative radar altimeter, and high-precision orbit determination (POD), which are expected to be at least as accurate as ENVISAT's. For this mission, the potential of innovative SAR mode is undoubtable, however, LRM mode is also of interest because it insures the continuity of data with the other missions, notably at high latitudes where it is now the only altimeter available between April 2012 (Envisat end of mission) and February 2013 (AltiKa launch)...

This paper focuses on the LRM data and assesses Cryosat-2 data quality over ocean. It quantifies the system performances for the sea level calculation for large and mesoscale... Stability of the different parameters including the Sea Level is also analyzed in order to anticipate the potential of this mission to complete the altimetric time series (when the period is long enough) for the climate studies (notably Sea Level Rise).

In this paper, the data and the analyses methods used to quantify the performances is described, including potential L2P upgrades (editing...). This paper also includes preliminary comparisons to in situ data (Temperature Salinity Profiles and Tide Gages near coasts) that give an absolute reference to detect drifts (when the time series is larger) and or geographically correlated patterns. Finally, few comparisons to other precise altimetric missions (Envisat and Jason-2) are proposed. They are essential to assess data quality, as well as to allow combination of altimeter for applications and operational oceanography purpose.