Water vapour intercomparison effort in the frame of the Convective and Orographically-induced Precipitation Study

The main objective of this work is to provide accurate error estimates for the different water vapour profiling sensors based on an intensive inter-comparison effort. The inter-comparison, performed in the framework of COPS-Convective and Orographically-induced Precipitation Study (01 June-31 August 2007), involves airborne and ground-based water vapour lidar systems, radiosondes with different humidity sensors, GPS and Microwave radiometers (MWR). Simultaneous and co-located data from different sensors are used to compute relative bias and root-mean square (RMS) deviations as a function of altitude.