Simulation of the experiment data from WINDII flown on the UARS/NASA satellite

The WINDII instrument (Wind Imaging Interferometer) is dedicated to the measurement of the temperature and wind in the upper Earth's atmosphere. It was launched with the NASA-UpperAtmosphere Research Satellite on September 12, 1991. It analyzes the natural emission lines of the atmosphere by an inteiferometric method to extract the temperature and wind information. Such a mission requires building the instrument, preparing its modes of operation, its scientific data processing, and evaluating its performance. To achieve these last tasks simulated data are needed. Which is why we have developed a quite extensive code of simulation which consists of several models: instrument, atmosphere to be observed (temperature, wind and intensity), orbit and attitude, and instrumental noises. The simulated data have permitted the evaluation of certain instrument effects and suggested some improvements of design. The effects of the various sources of noise have been studied. Scenarios of observations have been derived allowing the study of the scientific data processing algorithms and evaluation of their performances. Simulation of such a space instrument has been seen as an essential step in the design of the mission.