Relative range bias drifts revealed by a multi-mission crossover analysis: from TOPEX to Sentinel-3

Denise Dettmering (Deutsches Geodätisches Forschungsinstitut der Technischen Universität München (DGFI-TUM), Germany)


Christian Schwatke (Deutsches Geodätisches Forschungsinstitut der Technischen Universität München (DGFI-TUM), Germany)

Event: 2018 Ocean Surface Topography Science Team Meeting

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

Presentation type: Type Poster

A global multi-mission cross-calibration enables the combination of different altimetry missions with various sampling characteristics and measurement periods. In addition, a cross-calibration is able to provide information on the quality of single missions and to reveal, e.g., instrument drifts or geographically correlated error patterns.

DGFI-TUM is performing multi-mission altimeter crossover analysis (MMXO) on a regular basis in order to estimate relative radial errors between the different altimeter systems operating simultaneously. The cross-calibration is realized globally by minimizing a large set of single- and dual-satellite sea surface height (SSH) crossover differences computed between all contemporaneous altimeter systems. The total set of crossover differences creates a highly redundant network and enables a robust estimate of radial errors with a dense sampling for all altimeter systems analyzed. An iterative variance component estimation is applied to obtain an objective relative weighting between the different altimeter systems.

This contribution is focused on relative instrument drifts between contemporaneous altimeter systems. MMXO results for the most recent missions, i.e. Sentinel-3 and Jason-3, will be presented as well as results from the first years of the existing 25-years time series: The relative drift behavior between TOPEX and ERS will be analyzed in order to set light on systematic differences between these missions, which might be related to an absolute drift of the TOPEX site A altimeter system.

Poster show times:

Room Start Date End Date
Foyer, Salao Nobre & tent Thu, Sep 27 2018,18:00 Thu, Sep 27 2018,20:00
Foyer, Salao Nobre & tent Fri, Sep 28 2018,14:00 Fri, Sep 28 2018,15:00
Denise Dettmering
Deutsches Geodätisches Forschungsinstitut der Technischen Universität München (DGFI-TUM)