Advanced Land Observing Satellite-2 “DAICHI-2” (ALOS-2): Overview and operational status

This article presents an overview and discusses the significance of the Advanced Land Observing Satellites-2 (ALOS-2, “DAICHI-2”). ALOS-2, the successor to the ALOS synthetic aperture radar (SAR) mission, was launched in 2014 and has been operating smoothly beyond its design mission life of seven years. The Phased Array-type L-band SAR-2 (PALSAR-2) on board ALOS-2 has shown its maximum contribution in the basic observations of global land areas with time series acquired at high resolution and in emergency observations during natural disasters. This article introduces an overview of ALOS-2 and the major results of its operation and calibration more than 10 years after launch. In addition, activities related to research and applications mainly using ALOS-2 data are presented. This experience will be applied to ALOS-4.