Absolute Calibration of the MTVZA-GY Microwave Radiometer Atmospheric Sounding Channels

摘要

The microwave MTVZA-GY imager/sounder is one of the key instruments onboard the Meteor-M N2 satellite (launched in July, 2014). The MTVZA-GY data assimilation in numerical weather prediction (NWP) schemes should provide a significant positive impact. The method of absolute calibration for MTVZA-GY atmospheric sounding channels is under discussion. Absolute calibration means converting the antenna temperatures, measured by the MTVZA-GY, to the sensor brightness temperatures and is performed using accurate radiance simulations for selected regions. The NWP products are used as input to the radiance simulation code together with the data on surface emissivity. For the sea surface, emissivity is calculated with a parameterized model. For the land surface, emissivity is specified using a public database. The results of absolute calibration of the MTVZA-GY temperature (52-57 GHz) and humidity (183.3 GHz) sounding channels are presented.