Total Solar Irradiance Monitor for the FY-3B Satellite – Space Experiments and Primary Data Corrections

We present space experiments of the Total Solar Irradiance Monitor (TSIM) on the FY-3B satellite. The total solar irradiance (TSI) has been measured by TSIM/FY-3B continuously for nearly four years, with some short data gaps. Overlapping measurements of the TSI are provided by the TSIM, with three electrical substitution radiometers that are mounted with different alignment angles onto the leading face of the satellite. TSI measurements are normalized to a distance of 1 AU and zero velocity with respect to the Sun. The relative uncertainty in the TSI measurements is 910 parts per million. TSI values measured with TSIM/FY-3B are around 1365 W m−2, slightly lower than VIRGO/SOHO and higher than TIM/SORCE values. Most of the time, it is found that short time-scale variations in TSI detected by TSIM/FY-3B agree with other space TSI instruments.