Satellite observations from passive microwave and infrared instruments aboard environmental satellites are very vital for studies related to weather and climate. However, these observations are subject to different errors and uncertainties such as sensor degradation, calibration drift, and geolocation error. This session supports all activities related to calibration, validation, bias correction, inter-calibration, and geolocation correction of the observations from passive microwave and infrared instruments including, but not limited to, HIRS, CRIS, AIRS, IASI, AMSU, MHS, TRMM, ATMS, SAPHIR, SSMI and SSMI/S. This session also supports similar activities that are used to develop long-term climate data records from these observations.