Sea-Surface-Temperature Retrieval at Higher Spatial Resolution in the Satellite-Borne Microwave Radiometer AMSR2 Follow-On Mission

The Advanced Microwave Scanning Radiometer-2 (AMSR2) follow-on mission is currently being considered, and end users are demanding the acquisition of sea-surface temperature (SST) with higher spatial resolution. However, it is assumed that the AMSR2 baseline design will be followed as much as possible to shorten the development period. The SST image retrieved from the 6- or 10-GHz brightness temperatures includes random “snow” noise due to the thermal noise originating from the receiver components. In AMSR2, simple spatial averaging was performed to reduce such random noise to obtain clear SST images, but this method is not suitable for acquiring SST images with the high spatial resolution because it degrades the spatial resolution. In the AMSR2 follow-on mission, the algorithm for the AMSR2 L1R product (Backus–Gilbert method) will be applied to reduce random noise without degrading the spatial resolution. In addition, we propose equipping not only a 10-GHz channel with the conventional frequency band but also that with an extended frequency band. This letter presents the results of the study that led to these proposals required to obtain clear SST images with higher spatial resolution in the AMSR2 follow-on mission.