Cross-platform calibration of SMMR, SSM/I and AMSR-E passive microwave brightness temperature

The long time series of passive microwave satellite data (SMMR, SSM/I and AMSR-E) have provided important information about the earth surface science and climate research in the past three decades. Due to the update of satellite-based radiometers and their platforms, some systematic parameters are different, and there are biases among brightness temperature in different periods, which lead to inaccuracy of some parameters' retrieval. In order to obtain consistent brightness temperature datasets, and provide convenience for the researchers using these data, it is necessary to calibrate the brightness temperature from different sensors. Considering the difference between the variance of brightness temperature from different sensors on cold and warm region at the cross time, this paper analyzed the brightness temperature on the cold and warm region respectively. On the cold region, because the diurnal temperature variation is very small, the influence on brightness temperature caused by difference of the satellites overpass time during the overlap period can be ignored. The brightness temperature data at 18GHz and 37GHz channels of Nimbus-7 and 19GHz, 37GHz channels of DMSP on the Antarctic or the Greenland glacier during the overlap period were analyzed. On the warm region, due to the reason that the daily variance of temperature contributes a lot to the difference of brightness temperature from different sensors during the overlap period, the diurnal cycle of surface temperature on the Sahara desert region was analyzed, and base on it, the influence of temperature to brightness temperature was eliminated. Finally, considering the two regions, the cross coefficients of calibration were estimated.