Abstract's details
ERS-2 mission reprocessing for long-term continental surfaces studies
CoAuthors
Event: 2015 Ocean Surface Topography Science Team Meeting
Session: Instrument Processing: Measurement and retracking (SAR and LRM)
Presentation type: Type Poster
Contribution: PDF file
Abstract:
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.
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.