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About ALOS-1

ALOS Satellite Image
ALOS-1 mission

The Advanced Land Observing Satellite (ALOS-1) was a Japanese Earth-imaging satellite from the Japan Aerospace Exploration Agency (JAXA) that launched on 24 January 2006 and completed its operational phase on 12 May 2011 after failing due to a power anomaly.

ALOS-1 is part of ESA's Third Party Missions Programme, in which ESA has an agreement with JAXA to distribute data products from the mission.

ALOS-1 Objectives

The ALOS-1 mission objectives were:

  • Providing its user community with data of sufficient resolution to be able to generate 1:25,000 scale maps
  • Developing Digital Elevation Models and related geographic data products
  • Performing regional observation to aid sustainable development goals
  • Surveying natural resources
  • Develop sensor and satellite technology for future Earth-observation missions
  • Disaster monitoring around the world.

ALOS-1 Instruments

PRISM instrument
The Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) was a panchromatic radiometer with 2.5 m spatial resolution at nadir. Its extracted data was designed to provide highly accurate digital surface models (DSM).
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PALSAR instrument
The Phased Array L-band Synthetic Aperture Radar (PALSAR) was a successor sensor to the SAR on-board JERS-1 with more advanced functions such as higher spatial resolution and ScanSAR mode.

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The Advanced Visible and Near-Infrared Radiometer-2 (AVNIR-2) was a four band (visible and near-infrared) radiometer with a resolution of 10 m, designed for observing land and coastal zones.

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The ALOS-1 instruments were capable of observing the entire surface of the Earth:

  • Any place within two days
  • Around the equator: about 60% of the area within one day
  • At latitudes of 35°: about 70% of the area within one day
  • At latitudes above 55°: any place every day (provided there is no cloud cover for the optical instruments)

Night-time observation modes: PALSAR (Note: AVNIR-2 and PALSAR are able to operate simultaneously).

PALSAR calibration is provided with PARC (Polarimetric Active Radar Calibrator) as well as by other means.


Non-scientific measuring instruments:

  • AOCS (Attitude Orbit and Control System)
  • RRA (RetroReflector Array)
  • SST (Star Tracker)

ALOS-1 Data