Operational Calibration Result of the Advanced Land Observing Satellite-2 (ALOS-2)

This paper summarizes an operational calibration result of the Advanced Land Observing Satellites-2 (ALOS-2, nicknamed "DAICHI-2"). ALOS-2, the successor to the Phased Array-type L-band Synthetic Aperture Radar (PALSAR) onboarded ALOS "DAICHI" from 2006 to 2011, was launched in 2014 and has been operating smoothly beyond its design mission life of 7 years; the PALSAR-2 onboard ALOS-2 has shown its maximum contribution in practical applications by the basic observations of global land areas with time-series high resolution, and in emergency observations during natural disasters. The observation capability of PALSAR-2 has been improved over PALSAR e.g., a finer spatial resolution of 1 x 3m by the Spotlight observing mode, a wider swath width of 490 km by the ScanSAR mode, and a right-and-left looking function. To take full advantage of these capabilities, sensor calibration is extremely important. This paper reports the latest operational calibration result of PALSAR-2 during more than 9 years of its mission operation period.