Global and regional altimetry CAL/VAL and science

Author:

Marc Naeije - (AS/SpE)

Co-Investigator(s):

Rania Altiparmaki (AS/SpE)
Ernst Schrama (AS/SpE)

Abstract:

This proposal lists the research on ocean surface topography implemented at the Astrodynamics and Space missions Chair, Dept. of Space Engineering (AS/SpE), focusing on CAL/VAL activities related to altimetry and gravimetric observations. This is an on-going activity at the department and elaborates on previous (OSTST/SWT) projects dealing with calibrating, validating, studying and applying data from all altimeter missions to date, now also including the JASON-3 and the SENTINEL-3 missions. Main topics include a) the maintenance, development and service of the Radar Altimeter Database System (RADS), b) the related altimeter calibration and validation issues and orbit accuracy assessment and improvement, c) the scientific use in multidisciplinary studies, combining altimetry with gravity data to improve circulation models, address water and ice mass changes, improve ocean tidal modelling, and enhance mesoscale variability, and d) the long-term global, regional and local sea level variation using a mix of altimetry and other information sources like GNSS, InSAR and tide gauges. Connected to the work for RADS we address also the preparation for new altimeter missions (like Sentinel-6) and new altimeter processing concepts like FF-SAR altimetry. Connected to CAL/VAL we also address sampling issues and strategies to optimally combine the available altimetry and participate in discussions on future altimeter instruments and constellations. As an extension to the current research we recently hired a PhD to investigate the impact of waves, in particular swell, in retrieval of sea level from delay/Doppler altimetry, in order to come up with an improved retrieval and an improved sea state bias and swell correction.