Uncertainty Characterization with FRM Standards for Satellite Altimetry Calibration: Lessons from the past and roadmap to the future.

Stelios Mertikas (Technical University of Crete, Greece)


Craig Donlon (European Space Agency/ESTEC, The Netherlands); Pierre Féménias (European Space Agency/ESRIN, Italy); Demitris Galanakis (Space Geomatica P.C., Greece); Xenophon Fratzis (Technical University of Crete, Greece); Achilles Tripolitsiotis (Space Geomatica P.C., Greece)

Event: 2018 Ocean Surface Topography Science Team Meeting

Session: Quantifying Errors and Uncertainties in Altimetry data

Presentation type: Type Poster

Satellite altimetry today provides exceptional means for absolute and undisputable monitoring of changes in sea level and inland waters (rivers and lakes), over regional to global scales, with accuracies of [mm/yr] and with respect to the center of mass of the Earth. Altimetry also measures wind speed on sea surface, sea state, determines ocean circulation, bathymetry, but also monitors melting rates of ice sheets in Arctic, Antarctica, and the Himalayas and observes the amounts of the sea ice and freeboard; All these with an accuracy less than 1cm from an attitude of 800-1300 km above the earth’s surface.

To continue doing that, altimetry system’s responses have to be continuously monitored and controlled for their quality, biases, errors, drifts, etc. Relations among different missions have to be established on a common and reliable earth-center reference system, maintained for a long period of time (at least 20 years).
At this stage, it is high time to (1) Build upon commonly adopted procedures, protocols and uncertainty for Cal/Val, (2) Provide control and checks for monitoring altimeter degradation as fast as possible, (3) Connect one altimetry mission with another, seamlessly and smoothly, (4) Adopt a stable framework for international and interdisciplinary cooperation, (5) Allow data integration between different scientific fields and disciplines, (6) Set standards for measurements and results between various Cal/Val facilities, (7) Ensure Cal/Val procedures, results are well documented and traceable to SI units, (8) Provide transparent protocols and best practices for establishing new Cal/Val sites and finally, dissipate responsibility to end user to decide the extent of fit for his requirements.

This presentation generates a summary roadmap to be used by all satellite altimetry Cal/Val community to (1) support accuracy in scientific and monitoring data we produce and evaluate, (2) to provide accurate information presented to the Public for understanding effects of sea level rise to their lives, and finally (3) to help make the right decisions, and put into action the right Policies for climate change. Ways to express uncertainty will be given to meet the standard of Fiducial Reference Measurements but also provide SI-traceable (Système International d'Unités) calibration results.


Poster show times:

RoomStart DateEnd 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
Stelios Mertikas
Technical University of Crete