Dec. 7, 2015

The Japan Aerospace Exploration Agency (JAXA) has completed operation of the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) at around 2:30 p.m. on December 4, 2015 (Japan Standard Time, JST).

The AMSR-E has been operated for over nine years as an onboard device installed in the US Earth Observing Satellite (EOS) “Aqua”, after its launch on May 4, 2002. At 3:58 p.m. on October 4, 2011 (JST), the AMSR-E reached its limit to maintain the antenna rotation speed necessary for regular observations (40 rotations per minute), and the radiometer automatically halted its observation and rotation. After observation by the AMSR-E was suspended, JAXA prepared a recovery plan with NASA engineers, and the AMSR-E restarted its observation in slow rotation mode (2 rotations per minute) on December 4, 2012. Although the AMSR-E observation data in slow rotation mode limited to observe sparse areas, it was used for cross-calibration with the AMSR2 (successor of the AMSR-E) onboard the Global Change Observation Mission-Water “SHIZUKU” (GCOM-W) since its launch on May 18, 2012, in order to produce and provide a consistent and long-term dataset between the AMSR-E and AMSR2 by correcting their differences in sensor properties.

However, the AMSR-E reached its limit to maintain the antenna rotation speed necessary for slow rotation mode (2 rotations per minute,) and it automatically halted its observation and rotation at around 2:30 p.m. on December 4, 2015 (JST). As December marks just three years of simultaneous AMSR-E and AMSR2 operation, and because we obtained sufficient data necessary for cross-calibration, we decided to complete operation of the AMSR-E at this time.

At present, the AMSR2 has been operating as the successor of the AMSR-E in the same orbit. The AMSR2 continues the long-term, high-resolution observation of global water cycle variation by the AMSR-E and related operational utilization, which are new fields exploited by the AMSR-E (see the Appendix for more details). Moreover, the AMSR2 contributes on an ongoing basis to both fields of practical application and water cycle/and climate variation research.