ERS-2 mission reprocessing for long-term continental surfaces studies

Benoît Legrésy ((1) CSIRO Oceans and Atmosphere Flagship, Hobart Tasmania, Australia. (2) LEGOS/CTOH, UMR5566 CNRS-CNES-IRD-Université de Toulouse III. (3) ACE-CRC, Hobart, Tasmania, Australia., France)

CoAuthors

Fernando Niño (CTOH-LEGOS-IRD, UMR5566 CNRS-CNES-IRD-Université de Toulouse III., France); Fabien Blarel (CTOH-LEGOS-CNRS, UMR5566 CNRS-CNES-IRD-Université de Toulouse III., France); Frédéric Frappart ((1) LEGOS-GRGS, UMR 5566, CNES/CNRS/IRD/Université de Toulouse III. (2) GET-GRGS, UMR 5563, CNRS/IRD/Université de Toulouse III., France); Florence Birol (CTOH-LEGOS, UMR5566 CNRS-CNES-IRD-Université de Toulouse III., france); Sara Fleury (CTOH-LEGOS-CNRS, UMR5566 CNRS-CNES-IRD-Université de Toulouse III., France); Nicolas Fuller (CTOH-LEGOS-CNRS, UMR5566 CNRS-CNES-IRD-Université de Toulouse III., France)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Instrument Processing: Measurement and retracking (SAR and LRM)

Presentation type: Type Poster

Satellite altimetry has been a very powerful tool in oceanography and continental surface studies over the last 25 years. While instrument processing and retracking techniques have been improved over the years for all satellite missions towards ocean applications, less effort has been made for continental studies. ESA's ENVISAT mission has been updated regularly, improving the quality of processing of continental data, unlike the ERS missions.

The CTOH processed the ERS-2 waveforms (WAP data) with a new implementation of the Ice-2 retracker algorithm, adding improvements and corrections to make it compatible and homogenous with the ENVISAT mission, hence providing suitable grounds for continuity and long-term altimetry data analysis. The other differences with the REAPER ERS-2 product are: we used the newer Rudenko et al. (2014) orbit product, a dry troposphere correction using ERA fields valid over all surfaces (Blarel and Legresy, 2013), and a new Doppler correction valid over all surfaces using range rates (Blarel and Legresy, 2012). They have significant impact over continental surfaces.

Envisat/ERS-2 mission continuity is tested by cross-validating data obtained during the tandem phase when they flew with 30 minutes time separation. We show here the main validation and cross validation of the two missions. We find a good general agreement, but some differences in the ice-2 retracker behavior over continental surfaces which we discuss. We show a global validation, as well as of the actual height and radar measurements over the continents, over inland water bodies and over ice sheets. The high level (geophysical data record and beyond) product is available and distributed by the LEGOS/CTOH altimetry service.
 

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Benoît Legrésy
(1) CSIRO Oceans and Atmosphere Flagship, Hobart Tasmania, Australia. (2) LEGOS/CTOH, UMR5566 CNRS-CNES-IRD-Université de Toulouse III. (3) ACE-CRC, Hobart, Tasmania, Australia.
France
legresy@legos.obs-mip.fr