ALOS-2 science program

The Advanced Land Observation Satellite-2 (ALOS-2) will be launched in 2013 and will carry an L-band synthetic aperture radar (PALSAR-2) to a polar orbit with an altitude of 628 km and 14-day revisit time. Four mission objectives are disaster mitigation, environmental monitoring as represented by forest and cryospheric monitoring, land monitoring, and technology development. PALSAR-2 onboard ALOS-2 will provide 1-3-m high-resolution Spotlight and Strip with multiple polarizations with an imaging swath of 25/50/70 km, ScanSAR with dual polarizations with a 350/490 km swath, a shorter temporal baseline of 14 days and spatial baseline of within 1 km, emergency observation service within a 12-h delay for any global target and especially within a 72-h (74 h in the worst case) delay as synchronized observation with the archives, i.e., same off-nadir and observation mode, and ScanSAR interferometry with more than 90% global beam synchronization. The ALOS-2 science program initiates the calibration, validation, and application research of PALSAR-2/ALOS-2 and Pi-SAR-L2. As application research, disaster mitigation and the urban-area monitoring using the high-resolution data should contribute significantly to safety since disasters have occurred frequently and globally in the recent past. High-resolution and multi-polarimetric SAR with a shorter revisit time ensures quicker detection of land changes. In this paper, we summarize the contents of the ALOS-2 science program and its expected outcomes. Some application examples of disaster mitigation using recent high-resolution SARs, i.e., Pi-SAR-L2 and PALSAR, are also introduced.