Use of Radar Information for Assimilation into Atmospheric Models: a Review, part I: pre-processing of Radar Data

Within the framework of the European Co-operation in the field of Science and Technical research (COST) program, currently action 717, entitled ``Use of Radar Observations in Hydrological and NWP models'' is running (1999-2004). Working group three (WG3) of this action focusses on the assimilation of radar data into atmospheric models. One of the first activities of this working group has been a review of the state-of-the-art in assimilation of radar data into atmospheric models, including pre-processing of the data for assimilation.

The review has been divided into three sections: one section on the pre-processing of radar reflectivity and Doppler data, one section on the assimilation of radar reflectivity data into Numerical Weather Prediction (NWP) models, and a final section on the assimilation of Doppler data into NWP models. In the first section, an overview of the pre-processing techniques and limitations of radar reflectivity and Doppler data is presented. Possible sources of errors, like attenuation, clutter, velocity aliasing, and range aliasing, are discussed. The second and third section will be presented in part II of this contribution.

The content of the first section of the review will be highlighted in the presentation at the conference, and the complete review and corresponding bibliography will be made available.