Data from a bistatic radar network (including the recently implemented measurements of near-surface refractivity) are used to retrieve the 3D-wind field, pressure, temperature, humidity, liquid water, cloud, and water vapor contents. The assimilation of these measurements is performed with a variational method, where a model is used as a weak constraint. The retrieved fields will be used for forward data assimilation in a numerical model.

Key words: bistatic radar, retrieval, variational method, data assimilation