Real-Time Quality Control of Wave Observations in the North Sea

Abstract

The use of ocean wave data in new data assimilation techniques prompted the development of a real-time quality control system for wave height and wave period observations. Over the North Sea, a relatively large number of wave observations, as well as a reliable wave model, are available. Therefore, a variety of tests can be made, allowing for a quite sophisticated wave-data quality control system. The system uses some of the ideas of Gandin's comprehensive quality control. In particular, an ensemble of single-variate tests is used instead of one large multivariate test, and data are not rejected and thrown away in successive tests but can be rehabilitated until the very end. Three months of data have been used to test the system. The decisions of the system are found to agree with manual analyses. The statistical properties of the accepted and rejected data are checked. After quality control, the residuals of the quality control tests have almost Gaussian distributions.