About ALOS

About ALOS

ALOS Main Specifications
Launch date January 24, 2006
Launch vehicle H-IIA
Launch site Tanegashima Space Center, Japan
Spacecraft mass Approx. 4 tons
Generated power Approx. 7 kW (at EOL)
Life Designed life : 3 years,
Target : 5 years
Orbit Sun-synchronous Sub-recurrent
Revisit Time : 46 days
Sub cycle : 2 days
Altitude(at Equator) : 691.65 km
Inclination : 98.16°
Attitude determination accuracy Within 2.0 x 10 -4°
(off-line, with GCP)
Position determination accuracy Within 1 m (off-line)
Data rate 240 Mbps (Via Data Relay Test Satellite)
120 Mbps (Direct transmission)
Onboard data recorder Solid-state data recorder (90 GB)

ALOS, Advanced Land Observing Satellite, is the world's top class land observing satellite launched in January 2006 by Japan Aerospace Exploration Agency (JAXA) and carries a nickname "DAICHI"


Launched by JAXA on January 2006, ALOS, also known as “DAICHI“, is among the world’s largest earth observation satellites. It ended operation on May 2011 after having imaged about 6.5 million scenes of the entire world during it 5 year lifespan.

Primary Mission of ALOS

Primary mission of ALOS is to make contributions to the following fields.

◆Cartography

Create and update maps (1:25,000 scale) over Japan as well as other countries, particularly in the Asia-Pacific region.


◆Regional observation

Perform regional environment observation indispensable for "sustainable development" (i.e., harmonization between the earth environment and development) in all parts of the globe.


◆Disaster monitoring

Ascertain the status of consequences of large-scale disasters.


◆Resource surveying

Conduct resource surveying.


◆Others: Technology development

Contribute to technology development necessary for future earth observation.

Overview and Components of ALOS

ALOS has three earth-observing sensors: Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) for detecting elevations with high precision, Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) for observing land coverage highly accurately, and Phased Array type L-band Synthetic Aperture Radar (PALSAR) for observing land areas day and night regardless of atmospheric weather conditions.

Data Reception

ALOS, one of the world's largest earth observing satellites, is aimed to acquire land observation data on the global scale with high resolution; hence, the acquired data is huge in size.


To handle this situation, the observed data are transferred not only via direct reception (downlinking) at the EOC but also via Data Relay Test Satellite (DRTS), so that observation data acquired elsewhere other than around Japan are promptly received even when the ALOS is flying on orbits outside the EOC's reception cone.


DRTS is a data relay satellite, so-called "KODAMA", which was launched in September 2002 on the H-IIA launch vehicle from Tanegashima Space Center, Japan. It is a geostationary communication satellite, relaying communication between ground stations and spacecraft and other space vehicles orbiting at low- to medium-altitudes (300-1000 km). Such a relaying capacity contributes to a drastic expansion of the scope of real-time communication between low- to medium-orbit space vehicles and ground stations.


△ Conceptual diagram of direct data reception from ALOS.
△ Conceptual diagram of data reception via DRTS)

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Contact information : order@alos-pasco.com

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Copy right of images used in this website is as follows.

ALOS-2(PALSAR-2),ALOS(PRISM and AVNIR-2): JAXA

ALOS(PALSAR): METI and JAXA