The Geostationary Interferometric Microwave Sounder (GIMS) is a new concept of atmospheric microwave sounder for China's future geostationary Earth orbit meteorological satellite (FY-4). A novel self-calibration method for interferometric radiometers with a rotating thinned array, particularly for GIMS, has been proposed in this letter. Compared with the traditional relative phase calibration approach, neither dedicated hardware nor dedicated calibration working model is needed to achieve the relative phase calibration in this novel interelement phase calibration. The self-calibration approach is inherently merged with the nominal observation working model of GIMS, owing to the continuous array rotating of the GIMS instrument. A running average scheme has been introduced into the self-calibration approach to enhance the signal-to-noise ratio of the calibration data, which is normally very low with the natural earth scene. The method is demonstrated by both simulation and field imaging experiment.
