Tanvir Isalm (JPL, USA)

The Jason-3 mission includes a three-frequency microwave radiometer, named the Advanced Microwave Radiometer (AMR), to provide a correction for the wet tropospheric path delay. This system is based on a similar system flying on Jason-2. This paper will focus on the post-launch calibration and performance assessment of the Jason-3 AMR relative to independent on-Earth calibration sources and the Jason-2 AMR during the tandem period. Both the brightness temperatures and the retrieved geophysical products will be assessed. A new feature for the Jason-3 mission is a radiometer cold sky calibration maneuver. Roughly every 60-days, the spacecraft is pitched to about 80 degrees, pointing the radiometer main beam to cold space. The sky is a stable 2.7K calibration source that will be used through the Jason-3 mission to track and correct for radiometer drift. An analysis will be presented of the cold sky calibrations to date as well as the prospect for the stability of the Jason-3 radiometer record given these calibrations. A similar calibration maneuver was started for Jason-2 toward the end of the tandem period and will be continued through the end of the mission.