ALOS (Advanced Land Observing Satellite) is a Japanese satellite designed to observe and map Earth's surface, to enhance cartography, monitor natural disasters, and survey land use and natural resources to promote sustainable development. The four-ton ALOS follows JERS and ADEOS, and will extend the database of these earlier satellites using three remote-sensing instruments: the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) for digital elevation mapping, the Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) for precise land coverage observation, and the Phased Array type L-band Synthetic Aperture Radar (PALSAR) for day-and-night and all-weather land observation.

ALOS had been scheduled for deployment in 2003; however, the failure of a number of recent Japanese satellite launches led to various delays. ALOS was eventually launched by an H-2A rocket from Tanegashima on 24 January 2006.