FY-3 satellite Ultraviolet Total Ozone Unit.

FY-3 satellites are Chinese second-generation polar orbit meteorological satellite series. Ultraviolet Total Ozone Unit (TOU) is one of the main payloads on FY-3 satellite and the first instrument for daily global coverage of total ozone monitoring in China. The main purpose of TOU is to measure the Earth backscatter ultraviolet radiation for retrieving daily global map of atmospheric ozone. TOU will provide the important parameters for environmental monitoring, climate forecasting and global climate changing research. At present, the in-orbit testing of TOU has accomplished and won a consummation, and it will be delivered to National Satellite Meteorological Center for the operational phase of the project. In this paper we introduce the instrument of TOU and its measuring principle, in general. We also analyze the recent working status of the instrument, including the sensitivity, measuring precision of solar irradiance, diffuser degradation and wavelength drift. The inversion results show that TOU can provide good global ozone maps, and a comparison with the OMI total ozone product shows that their RMS deviation is about 5%. It is indicated that the satisfied global distribution of total ozone can be obtained through TOU observational data and self-developed inversion method. [ABSTRACT FROM AUTHOR]