CEOS Member Agency Operated
Mid-Resolution Optical Land Surface Imaging Satellite Systems
Mid-resolution optical LSI satellite systems are spaceborne land remote
sensing systems that image the Earth’s land surface in visible, near-infrared,
shortwave infrared, and thermal infrared wavelengths with spatial resolutions
between 10 meters and 100 meters. Currently, nine CEOS member space agencies
operate such systems:
NASA, USGS, CNES, ISRO, JAXA, INPE, CAST, CONAE, and GISTDA.
Since 1972, the land remote sensing systems launched by these agencies have
collected an enormous volume of image data that has great potential value to
the global society because of the good that can be accomplished from the
application of these data to a broad range of scientific, social, and practical
problems and issues. The data have been utilized in a variety of government,
public, private, and national security applications. Examples include land and
water management, global change research, disaster management, oil and mineral
exploration, agricultural yield forecasting, pollution monitoring, land surface
change detection, cartographic mapping, and countless others.
Landsat Satellites – USA
The first Landsat satellite was launched by the National Aeronautics and
Space Administration (NASA) in July, 1972. Known initially as the Earth
Resources Technology Satellites (ERTS), the Landsat satellites have been the
workhorse for mid-resolution, optical land surface imaging from space. A
total of six Landsat satellites have achieved orbit, and they have provided
an uninterrupted record of calibrated image data of the global land surface
for the past 36 years with unprecedented quality, detail, and coverage.
Landsat satellites have carried multiple remote sensor systems and data relay
systems along with attitude-control and orbit-adjust subsystems, power supply,
receivers for ground station commands, and transmitters to send the data to
ground receiving stations. Landsat satellites are now operated by the U.S.
Geological Survey (USGS), and
data are available to all users at no cost by visiting
the Earth Explorer
or GloVis.
Landsat 1 carried two imaging instruments: the multispectral scanner
(MSS), which had four spectral bands with 80m spatial resolution, and a
three-band return bean vidicon (RBV) camera, but data from the RBV were
never used widely. Landsats 2 and 3, launched in 1975 and 1978, were
configured similarly. In 1984, Landsat 4 was launched with the MSS and a
new instrument called the thematic mapper (TM). TM instrument upgrades
included improved spatial resolution (30 meters) and three new spectral bands.
Landsat 5 was launched in 1984, and it carries the same instrument package as
Landsat 4. Landsat 5 continues to collect TM data, some 24 years after launch.
Landsat 6, which also carried a TM sensor, failed to achieve orbit in 1993.
Landsat 7, equipped with an enhanced thematic mapper, plus (ETM+) that includes
a 15m panchromatic band and 60m thermal band was launched in 1999. In 2003,
the ETM+ on Landsat 7 suffered a mechanical problem that substantially affects
the quality of the data collected, though it does continue to acquire global
data on a routine basis. The next Landsat satellite is scheduled for launch in 2011.
SPOT Satellites - France
The French SPOT satellite program consists of a series of optical remote
sensing satellites with the primary mission of obtaining Earth imagery for
land use, agriculture, forestry, geology, cartography, regional planning,
water resources and GIS applications. SPOT 1 was launched by the French
space agency, Centre National d’Etudes Spatiales (CNES) in February 1986,
and it was withdrawn from active service in December 1990. The first three
SPOT satellites had identical characteristics, with the high-resolution visible
(HRV) sensor acquiring image data in three spectral bands at 20m spatial resolution
and one 10m panchromatic band. The high-resolution visible and infrared (HRVIR)
sensor on SPOT 4 includes an additional SWIR band. The SPOT 5 satellite, launched
in 2002, carries two new high-resolution geometric (HRG) imaging sensors that
were derived from SPOT 4 HRVIR instruments, but which have 10m spatial resolution
in multispectral mode and 2.5m to 5m spatial resolution in panchromatic mode.
A single SPOT scene covers a 60km x 60 km area on the ground.
SPOT data are available on a commercial basis. Some programs have been set
up to support acquisition for science or education. For European scientists,
the CNES program ISIS
(http://www.isis-cnes.fr)
or ESA program TPM
(http://eopi.esa.int/Spot)
can provide SPOT data on a free basis or at a very low price. ESA programme
is also open to African and Canadian scientists. Users should check with the
local SPOT representative to determine availability of specific agreement that
may exist locally.
IRS Satellites - India
One of the important programs of the Indian Space Research Organization
(ISRO) is the development of space-based land remote sensing and supplying
data and services for Earth resources monitoring and management. The Indian
Remote Sensing (IRS) satellites comprise India's dedicated Earth resources
satellite system operated by ISRO. The primary objective of the IRS missions
is to provide India's unique institutional framework National Natural Resources
Management System (NNRMS) with remote sensing data to support the national
development. The operational IRS satellites have been planned basically under
three thematic series: land and water resources development and management,
cartography, and an atmosphere/oceans series. The first IRS land surface
imaging satellite, IRS-1A, was launched in 1988. Currently there are two
mid-resolution optical satellites of the IRS series in sun-synchronous low-earth
orbit, IRS-1D and Resourcesat-1 (IRS-P6).
IRS satellite data are available to users from India through the National Remote
Sensing Centre (NRSC) of India by visiting
www.nrsc.gov.in.
Users from outside
India may access IRS data from the Antrix Corporation, Ltd. by visiting
www.antrix.gov.in.
Earth Observation Satellites - Japan
Japan has been an active participant in the launch and operation of dedicated
mid-resolution land surface imaging satellite systems since the launch of the
Japan Earth Resources Satellite-1 (JERS-1) in 1992 by the Japan Aerospace
Exploration Agency (JAXA). JERS-1 carried an optical sensor called OPS that
had three visible and near IR (VNIR) bands, including one that was stereo-viewing,
and four shortwave infrared (SWIR) bands. JERS OPS data had 24m spatial resolution.
JAXA launched the Advanced Earth Observing Satellite (ADEOS) in 1996. ADEOS
carried a mid-resolution optical sensor called the Advanced Visible and Near-Infrared
Radiometer (AVNIR), which imaged the Earth’s surface in four VNIR bands at 16m spatial
resolution and one pan band at 8m spatial resolution with an 80km swath. In 2006, JAXA
launched the Advanced Land Observing Satellite (ALOS), which carries the AVNIR-2 sensor.
AVNIR-2 has four VNIR bands that image a 70km swath at 10m spatial resolution.
Data collected by the JERS-1 and ADEOS LSI sensors can be accessed from JAXA by visiting
https://www.eoc.jaxa.jp/iss/ jsp/indexEn.html.
ALOS AVNIR-2 data can be accessed through CROSS, the online search and order system
operated by Remote Sensing Technology Center of Japan (RESTEC), by visiting
https://cross.restec.or.jp/cross/CfcLogin.do?locale=en
In December, 1999, NASA launched another important Japanese mid-resolution
optical LSI satellite system named Advanced Spaceborne Thermal Emission and
Reflection Radiometer (ASTER) onboard its Terra satellite in cooperation with
Japan’s Ministry of Economy, Trade, and Industry (METI). ASTER acquires image
data in three VNIR, six SWIR, and five TIR bands with 15m, 30m, and 90m spatial
resolution, respectively, and one VNIR band also is acquired in stereo mode.
ASTER’s duty cycle on Terra is limited to 8%, so global data are not acquired
on a routine basis. However, more than 1.5 million ASTER scenes have been
acquired since launch, and virtually all parts of the global landmass have
been imaged by ASTER. ASTER data are readily available both from NASA and METI
by visiting one of the following sites:
http://imsweb.aster.ersdac.or.jp/ims/html/MainMenu/MainMenu.html,
https://wist.echo.nasa.gov/~wist/api/imswelcome/,
or http://glovis.usgs.gov/.
Earth Resource Satellites – China & Brazil
At the end of the 1980’s, Brazil’s National Institute for Space Research
(INPE) began the development of a civilian remote sensing satellite program
with the Chinese Academy of Space Technology (CAST). This program was one of
the first in the world involving two countries under development striving to
build and launch a satellite – an effort that brings difficult technical challenges.
The cooperation is now 20 years old, and three mid-resolution optical LSI
satellite systems have been launched successfully as a result. To achieve such
success, the cooperative effort had to overcome many obstacles, not the least of
which was language. Since the two countries have languages that are very different,
a third one had to be chosen to work as a common language. The cultures are very
different also, and adaptations from both sides had to be done so that both teams
could work together. Many other obstacles had to be overcome as the project evolved.
The initial signed agreement was for the development and launch of two
remote sensing satellites. In October 1999, the China-Brazil Earth Resources
Satellite-1 (CBERS-1), was launched from Taiyuan launch site in China. CBERS-1
carried three cameras: CCD (High Resolution CCD Camera) at 20m spatial resolution
and five bands (three visible, one NIR, and one panchromatic); WFI (Wide Field Imager)
at 260m spatial resolution and two bands (red and NIR); IRMSS (Infrared Multispectral
Scanner) at 80m spatial resolution (one panchromatic and two SWIR) and 160m spatial
resolution (TIR). CBERS-2 was launched in October 2003, and its sensor package was
identical to CBERS-1.
Prior to the launch of CBERS-2, CAST and INPE agreed to continue their cooperation
into the future. CBERS-2B was successfully launched in September 2007, and it also
carries the CCD and WFI sensors, but the IRMSS was replaced by HRC (High Resolution
Panchromatic Camera) at 2.7m spatial resolution. CBERS data from INPE are
available at no cost to the user by visiting
http://www.dgi.inpe.br/CDSR/.
SAC-C – Argentina
The Satellite de Aplicaciones Cientifico-C (SAC-C) is an international
cooperative mission between the Argentina Commission on Space Activities
(CONAE) and NASA, along with other international partners. The platform was provided by CONAE and
the launch by NASA. Instruments were provided by CONAE, NASA and cooperators in Denmark (DSRI),
France (CNES) and Italy (ASI) with testing support from INPE in Brazil. SAC-C was launched
in November 2000 with science objectives that included providing multispectral
images of the Earth in order to monitor the condition and dynamics of the
terrestrial and marine biosphere and environment. SAC-C carries three LSI
sensors, but only one is a mid-resolution optical sensor. The high-resolution
technological camera (HRTC) acquires image data in one VNIR panchromatic band
with 35m spatial resolution and a 90km swath. SAC-C HRTC data are collected
primarily over Argentina, and the data from the past six months are available
on-line and free of cost by visiting
http://catalogos.conae.gov.ar/conae_ftp_sacc/busquedas.aspx?st=SAC-C&leng=spa.
Older data also are available upon request.
THEOS – Thailand
The Geo-Informatics and Space Technology Development Agency (GISTDA) became
the most recent CEOS member space agency to launch a mid-resolution, optical LSI
satellite system when the Thailand Earth Observation Satellite (THEOS) achieved
orbit on October 1, 2008. THEOS carries a multispectral (MS) camera that acquires
images of the Earth’s surface in four VNIR bands at 15m spatial resolution across
a 90km swath. THEOS also carries a pan camera that acquires images with 2m spatial
resolution. THEOS products and availability are
described at the GISTDA site.
EO-1 - USA
The Earth Observing-1 (EO-1) satellite was launched on November 21, 2000 from
Vandenburg Air Force Base. A part of NASA’s New Millennium Program, the EO-1 mission
was developed to demonstrate new technologies and strategies for improved earth
observations. EO-1 carries two mid-resolution optical LSI sensors. The Advanced
Land Imager (ALI) which has six VNIR and three SWIR bands that are imaged at 30m
spatial resolution over a 37km swath and one panchromatic band that is imaged at
10m over the same swath. EO-1 also carries the Hyperion sensor which is a hyperspectal
sensor capable of resolving 220 spectral bands between 0.4 and 2.5 micrometers at
30m spatial resolution across a 7.7km swath. EO-1 data are available from the USGS
EROS Center by visiting
the Earth Explorer
or GloVis.
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