ALOS1

ALOS-1, also known as Daichi, was the first satellite in the Japanese Advanced Land Observing Satellite (ALOS) program operated by the Japan Aerospace Exploration Agency (JAXA). It was launched on 24 January 2006 from the Tanegashima Space Center aboard an H-IIA rocket. The spacecraft operated in a sun-synchronous, near-polar orbit at an altitude of about 700 kilometers, providing global land observation capabilities with a regular revisit pattern.

The mission carried three primary payloads. PALSAR (Phased Array type L-band Synthetic Aperture Radar) offered all-weather radar imaging in multiple modes and polarizations, enabling data collection day or night through clouds. PRISM (Panchromatic Remote-Sensing Instrument for Stereo Mapping) provided high-resolution optical stereo imagery for topographic mapping, using a tri-stereo configuration to derive digital elevation information. AVNIR-2 (Advanced Visible and Near Infrared Radiometer type 2) supplied visible and near-infrared imagery for land-cover and vegetation studies. Together, these instruments supported a range of applications from cartography and land-use mapping to disaster monitoring, forestry, and environmental research.

ALOS-1 was designed for an initial mission life of several years and, in practice, operated for longer than its nominal lifetime, contributing a substantial and ongoing data archive. The mission helped establish JAXA’s capacity in civilian Earth observation and served as a foundation for the subsequent ALOS-2 program, which built on the experiences and data products generated by ALOS-1. Data from the mission have been used by researchers, government agencies, and international partners to analyze land surfaces, monitor natural disasters, and support geospatial applications.