ALOS-2

ALOS-2
Name	ALOS-2
Operator	Japan Aerospace Exploration Agency
Mission type	Remote sensing, Earth observation
COSPAR ID	2014-030A
SATCAT	39766
Launch date	2014-05-24
Launch vehicle	H-IIA
Launch site	Tanegashima Space Center
Orbit	Sun-synchronous orbit
Instrument type	Synthetic Aperture Radar (SAR)
Status	Decommissioned

ALOS-2 ALOS-2 is a Japanese Earth observation satellite developed by the Japan Aerospace Exploration Agency for high-resolution synthetic aperture radar imaging. The platform supported applications across disaster response, land use, maritime surveillance, and scientific research, providing data to domestic agencies such as the Ministry of Land, Infrastructure, Transport and Tourism and international partners including NASA and the European Space Agency. The program followed earlier Japanese remote sensing efforts exemplified by ALOS and contributed to regional space collaboration with organizations such as JAXA’s counterpart agencies.

Overview

ALOS-2 was conceived as a follow-on to Japan’s prior optical and radar missions including ALOS, Daichi, and the Earth Resources Satellite series. Its primary payload was a phased-array L-band synthetic aperture radar designed to operate independently of daylight and cloud cover, supporting rapid-response imaging for stakeholders like the Japan Meteorological Agency, Geospatial Information Authority of Japan, and disaster relief organizations. Development involved Japanese industry leaders such as Mitsubishi Electric, NEC Corporation, and Mitsubishi Heavy Industries, while international collaboration drew interest from entities including JAXA’s research directorates and foreign ministries in the Asia-Pacific region.

Mission and Objectives

The mission objectives emphasized high-resolution surveillance, disaster monitoring, and geophysical science. Key goals included delivering sub-meter to multi-meter imagery for agencies like the Ministry of Defense (Japan), supporting tsunami and earthquake response for institutions such as the International Federation of Red Cross and Red Crescent Societies, and enabling interferometric analyses used by research centers like the Geological Survey of Japan and universities such as the University of Tokyo and Kyoto University. Strategic objectives also aligned with national policies articulated by the Cabinet Office (Japan) concerning resilience and infrastructure protection.

Spacecraft Design and Instruments

The bus architecture drew on heritage from missions supported by Mitsubishi Heavy Industries and incorporated a deployable active phased-array radar developed by industrial teams led by NEC Corporation and Mitsubishi Electric. The primary instrument was an L-band synthetic aperture radar capable of multiple polarization modes and spotlight, stripmap, and ScanSAR imaging, enabling applications parallel to capabilities demonstrated by RADARSAT-2, Sentinel-1A, and TerraSAR-X. Onboard subsystems included attitude control hardware influenced by designs used on H-IIA payloads and thermal systems similar to those on the Ikonos and Aqua spacecraft.

Launch and Mission Timeline

ALOS-2 launched on 24 May 2014 aboard an H-IIA rocket from Tanegashima Space Center, following launch campaigns coordinated with agencies such as Mitsubishi Heavy Industries and observation planning with international partners like NOAA. Early operations included commissioning phases monitored by JAXA ground teams and calibration activities involving international calibration sites and agencies such as NASA’s calibration groups. Over its operational life the satellite executed routine imaging campaigns, emergency taskings after events like earthquakes and typhoons affecting regions near Tohoku and Kumamoto Prefecture, and periodic orbit maintenance maneuvers consistent with sun-synchronous constellations.

Operations and Applications

Operational use spanned civilian and research domains. Emergency imaging supported response to natural disasters by organizations including the Cabinet Office (Japan), United Nations Office for the Coordination of Humanitarian Affairs, and regional disaster-management bodies. Environmental monitoring applications served agencies such as the Ministry of the Environment (Japan) and research institutes like the National Institute for Environmental Studies, while maritime surveillance activities provided data for the Japan Coast Guard and fisheries management authorities. Scientific applications included interferometric synthetic aperture radar (InSAR) studies conducted by institutions such as the Institute of Space and Astronautical Science and international university consortia.

Ground Segment and Data Products

The ground segment was operated by JAXA with data processing and dissemination partnerships involving the Geospatial Information Authority of Japan, commercial analytics firms, and academic data centers such as the Earthquake Research Institute. Routine products included single-look complex (SLC) imagery, geocoded products, and interferometric stacks used by researchers at entities like the National Research Institute for Earth Science and Disaster Resilience. Data distribution followed agreements with foreign agencies including NASA and the European Commission for cooperative projects and supported commercial value-added services delivered by private firms in Japan’s aerospace sector.

Notable Incidents and Legacy

During its service, the mission experienced operational events that drew attention from stakeholders such as JAXA and national emergency agencies. The satellite’s data were pivotal in post-event analysis after major tectonic events impacting Honshu and other regions, contributing to scientific publications from institutions including the University of Tokyo and international collaborations with researchers at Caltech and ETH Zurich. The program influenced subsequent Japanese Earth observation planning, informing successor efforts and policy discussions within the Cabinet Office (Japan) and industrial strategy debates involving companies like Mitsubishi Electric and NEC Corporation. Its legacy persists in archival datasets used by global initiatives coordinated among organizations such as NASA, the European Space Agency, and regional space agencies.

Category:Earth observation satellites Category:Satellites launched in 2014