Regional CalVal of Jason-2 and SARAL/Altika at three calibration sites: Corsica, Harvest and Bass Strait

Mathilde Cancet (NOVELTIS, France)


Sandrine Bijac (NOVELTIS, France); Christopher Watson (University of Tasmania, Australia); Bruce Haines (JPL/NASA, USA); Pascal Bonnefond (OCA/GEOAZUR, France); Florent Lyard (LEGOS/OMP/CNRS, France); Thierry Guinle (CNES, France)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Regional and Global CAL/VAL for Assembling a Climate Data Record

Presentation type: Type Oral

In situ calibration ensures regular and long-term control of the altimeter sea surface height (SSH) time series through comparisons with independent records. Usually, in situ calibration of altimeter SSH is done at the vertical of a specific CalVal site by direct comparison of the altimeter data with the in situ data.

However, for more than ten years, Noveltis has been developing a regional CalVal technique, which aims at increasing the number and the repeatability of the altimeter bias assessments by determining the altimeter bias both on overflying passes and on satellite passes located far away from the calibration site. The strong interest of this principle is to extend the single site approach to a wider regional scale, thus reinforcing the link between the local and the global CalVal analyses. It is also a mean to keep on calibrating a mission when good-quality in situ data happen to be missing at its dedicated calibration site.

The regional method was initially developed at the Corsican calibration sites of Senetosa and Ajaccio. The method was used to compute the biases of Jason-1, Jason-2 and Envisat (before and after the orbit change in 2010) at both sites, and proved its stability and generality through this cross-calibration exercise.

In 2013 and 2014, the regional method was successfully implemented for Jason-2 and Envisat at the Californian site of Harvest, in close collaboration with JPL, and at the Australian site in Bass Strait, in close collaboration with the University of Tasmania.

In 2015, it was implemented for the SARAL/Altika mission at the three calibration sites. The Jason-2 mission was also monitored at the three sites and the results are in very good agreement with the other calval groups.

The results presented in this paper highlight the numerous advantages of this technique for monitoring missions on any orbits such as CryoSat-2, HY-2A or the future Sentinel-3, Jason-3 and Jason-CS missions.

Oral presentation show times:

RoomStart DateEnd Date
Grand Ballroom 1 Wed, Oct 21 2015,14:45 Wed, Oct 21 2015,15:00
Mathilde Cancet