Simulation of the performance of WALES based on an end-to-end model

Abstract

WALES (Water Vapour Lidar Experiment in Space) is one of the experiments considered by ESA for selection as Earth Explorer Core mission in the frame of the Earth Observation Envelope Programme. WALES is expected to provide accurate and global 4-d water vapour fields with high vertical resolution from a low Earth orbit satellite. The expected performances of WALES have been simulated through the application of an end-to-end model. In this work we provide an assessment of WALES daytime performances in clear sky and cloudy conditions. Expected performances are expressed in terms of systematic and noise errors in dependence of altitude and SNR for three selected reference atmospheric models (tropical, sub-Artic winter and US Standard Atmosphere). An estimate of the major components of the systematic error is also provided. Real atmospheric data from existing lidar systems have also been considered to estimate the performances of WALES in variable atmospheric conditions, as well as to determine the effects on system performances associated with atmospheric inhomogeneities and variable cloud scenes.