Overview of the Global Change Observation Mission - Water 1st “SHIZUKU” (GCOM-W1)and Its Initial Calibration/Validation Results

Abstract

The Global Change Observation Mission (GCOM) aims to achieve global and long-term monitoring of the Earth by using two polar orbiting satellite observing systems with three consecutive generations. The GCOM-W1 (or “SHIZUKU”) satellite is the first satellite of GCOM-W (water) series, and was launched on May 18, 2012 (JST). The Advanced Microwave Scanning Radiometer-2 (AMSR2) on board GCOM-W1 continues its observation successfully more than one year. Basic characteristics of AMSR2 are similar to those of AMSR-E on board the Aqua satellite to continue the AMSR-E observations. During the initial calibration and validation period, AMSR2 brightness temperature values are being evaluated and characterized through methodologies such as the inter-calibration among similar microwave radiometers including the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), with the help of radiative transfer computations and global analysis field generated by meteorological agencies. Validation activities have been done to compare AMSR2 eight geophysical parameters with in-situ observations and/or other satellite instruments to evaluate accuracy of AMSR2 products. These results show that all products satisfied required release accuracy. JAXA has released AMSR2 brightness temperature (TB) and geophysical parameter (GEO) products to public though the GCOM-W1 Data Providing Service System since January 2013 for TB and May 2013 for GEO. AMSR2 products will be operationally utilized in various applications, such as numerical weather prediction, information of fishery fields, and so on. In future, AMSR2 data are expected to contribute in wider research and operational areas by archiving long term dataset and combining with data of AMSR-E and other instruments.