Development and Application of Validated Geophysical Ocean Wave Products from ENVISAT ASAR and RA-2 Instruments

Background

Ocean wind and wave measurements from satellites combined with global wave and atmospheric numerical models are dramatically changing our way of obtaining ocean wave information both for operational and climatological purposes.

Whereas wave climatology used to be produced from rather crude ocean atlases based on visual ship observations or time and site limited in-situ observations, satellite observations are now at the point of providing reliable global long-term wave statistics, often in combination with numerical wave model data. At the same time, through data assimilation in operational numerical models, satellite observations are contributing to improved short-term wave forecasts.  

Satellite wind observations, assimilated into atmospheric models also contribute indirectly by improving the atmospheric forecast and hence also the wind forcing in the wave models.

Synthetic Aperture Radar (SAR) is so far the only spaceborne instrument capable of measuring directional properties of ocean waves globally. Such information is known to represent the most important source of errors in numerical wave prediction models. By developing validated geophysical products from the SAR and Radar Altimeter (RA) missions, our knowledge on regional and global wave climatologies can significantly be improved. The European Space Agency (ESA) remote sensing satellites (ERS-1 and ERS-2) have provided the user community with global measurements of the ocean surface since 1991, comprising a unique set of more than 4 million ocean wave spectral observations, globally distributed over the world’s oceans and seas. The ERS global SAR and RA wave measurements will be extended and improved by the ENVISAT mission. The improvements will be achieved by better coverage, greater flexibility, more timely calibration data and new value-added products.

 

 

An EC research project co-funded by the Energy, Environment and Sustainable Development Programme within the topic 'Development of generic Earth observation technologies'.