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Global Change Observation Mission

April 30, 2024

GCOM (Global Change Observation Mission), is a JAXA project of long-term observation of Earth environmental changes. As a part of Japan's contributions to GEOSS (Global Earth Observation System of Systems), GCOM will be continued for 10 to 15 years with observation and utilization of global geophysical data such as precipitation, snow, water vapor, aerosol, for climate change prediction, water management, and food security. On May 18, 2012, the first satellite "GCOM-W" (nickname "Shizuku") was launched. On December 23, 2017, the second satellite "GCOM-C1" (nickname "Shikisai") was launched.

An artist's rendering of GCOM-W1.

GCOM-W edit

 
Launch of GCOM-W aboard a H-IIA rocket.

GCOM-W (Global Change Observation Mission – Water; nickname "Shizuku") is the first in the GCOM series. Its mission is to observe the water cycle. The satellite carries the AMSR2 (Advanced Microwave Scanning Radiometer 2) instrument, the successor to the AMSR-E carried by Aqua. This microwave radiometer will observe precipitation, water vapor, wind velocity above the ocean, sea water temperature, water levels on land areas, and snow depths. GCOM-W was approved in 2006, and development of the satellite started in 2007 with a mission budget of 20 billion Yen (US$200 Million). Mass of the satellite is 1990 kg.[1][2] Planned lifespan is 5 years. Polar orbit (altitude 700 km) with equator crossing local time on the ascending orbit is 13:30PM +/- 00:15.

GCOM-W was launched on May 17, 2012, via a H-IIA rocket, and it flies in a Sun-synchronous orbit as part of the "A-train" satellite constellation. It successfully began collecting data on July 4, 2012. Its planned lifespan of 5 years means that the satellite is set to operate until 2017, although JAXA hopes that it will last longer.[3]

GCOM-C1 edit

GCOM-C1 (Global Change Observation Mission – Climate; nickname "Shikisai"), the first satellite in the GCOM-C series, will monitor global climate change by observing the surface and atmosphere of Earth over the course of 5 years. Through use of its SGLI (Second generation GLobal Imager) optical instrument, it will collect data related to the carbon cycle and radiation budget, such as measurements of clouds, aerosols, ocean color, vegetation, and snow and ice. From its Sun-synchronous orbit (altitude 798 km), SGLI will collect a complete picture of Earth every 2–3 days with a resolution of 250-1000m, across the UV, visible, and infrared spectrums. Mass of the satellite is 2020 kg.[4] Equator crossing local time on the descending orbit is 10:30AM +/- 00:15.

GCOM-C was launched on December 23, 2017, via a H-IIA rocket.

Sensors edit

AMSR2 edit

AMSR2 (Advanced Microwave Scanning Radiometer 2) is an improved version of AMSR (aperture 2.0 m) on ADEOS II and AMSR-E (aperture 1.6 m) on NASA's Aqua satellite. By rotating a disc antenna (diameter 2.0 m) in 1.5 s period, it scans the Earth surface along an arc of 1450 km length. Reliability is better than AMSR and AMSR-E. Planned lifetime has been extended from 3 years to 5 years.

A new microwave band, namely 7.3 GHz, has been added. The 7.3 GHz band is for duplication and calibration of 6.925 GHz band. AMSR2 continues the legacy of AMSR-E, which also observed as part of the A-Train constellation.

AMSR2 observation frequency
parameter / frequency (GHz) 6.925/
7.3		 10.65 18.7 23.8 36.5 89.0 comments
column vapor 　 　 ○ ◎ ○ 　 　
column precipitable water 　 　 ○ ○ ◎ 　 　
precipitation 　 ○ ◎ ○ ○ ◎ 　
sea surface temperature ◎ ○ 　 ○ ○ 　 　
sea surface wind speed ○ ○ 　 ○ ◎ 　 　
sea ice density ○ 　 ◎ ○ ◎ ◎ 89 GHz is only for cloudless area
snowpack 　 ○ ◎ ○ ◎ ○ 　
soil moisture ◎ ◎ ○ ○ ○ ○ 　

Note: ◎ means the most important band for that purpose.

SGLI edit

SGLI (Second-generation Global Imager) is a multi-band optical radiometer and the successor of GLI sensor on ADEOS-II. It consists of two sensors: SGLI-VNR (an electronic scan) and SGLI-IRS (a mechanical scan). SGLI-VNR succeeds the technology of MESSR on MOS-1, OPS/VNIR on JERS-1, AVNIR on ADEOS, and AVNIR-2 on ALOS.

The number of channels of SGLI is 19, which is much less than GLI (36 channels). This is because SGLI carefully selected the essential bands for observations.

The swath size is 1150 km for SGLI-VNR and 1400 km for SGLI-IRS. Although a little reduction from GLI (all channels were mechanical scan with 1400 km swath), it has more bands with high-resolution (250 m). Polarimetry function has been added to SGLI-VNR, which helps detection of size of aerosol particles, enabling detection of source of the aerosols.

The lesson of GLI sensor's too big and too complicated structure, SGLI is divided to two simple systems, and the number of channels have been minimized to really essential bands, aiming at better reliability and survivability.

SGLI observation channels
instruments channel central wavelength bandwidth resolution target
SGLI-
VNR 		non-
polarization 		VN1 380 nm 10.6 nm 250 m terrestrial aerosol, atmospheric correction, ocean color, snow and ice
VN2 412 nm 10.3 nm vegetation, terrestrial aerosol, atmospheric correction, oceanic aerosol, photosynthetic active radiation, snow and ice
VN3 443 nm 10.1 nm vegetation, oceanic aerosol, atmospheric correction, photosynthetic active radiation, ocean color, snow and ice
VN4 490 nm 10.3 nm ocean color (chlorophyll, suspended sediments)
VN5 530 nm 19.1 nm photosynthetic active radiation, ocean color (chlorophyll)
VN6 565 nm 19.8 nm ocean color (chlorophyll, suspended sediments, colored dissolved organic matters)
VN7 673.5 nm 22 nm vegetation, terrestrial aerosol, atmospheric correction, ocean color
VN8 673.5 nm 21.9 nm
VN9 763 nm 11.4 nm 1000 m liquid cloud geometric thickness
VN10 868.5 nm 20.9 nm 250 m vegetation, terrestrial aerosol, atmospheric correction, ocean color, snow and ice
VN11 868.5 nm 20.8 nm
polarization P1 673.5 nm 20.6 nm 1000 m vegetation, terrestrial aerosol, atmospheric correction, ocean color
P2 868.5 nm 20.3 nm vegetation, terrestrial aerosol, atmospheric correction, ocean color, snow and ice
SGLI-
IRS 		short wave infrared
(SWIR) 		SW1 1050 nm 21.1 nm 1000 m liquid cloud optical thickness, particle size
SW2 1380 nm 20.1 nm detection of clouds over snow and ice
SW3 1630 nm 195 nm 250 m
SW4 2210 nm 50.4 nm 1000 m liquid cloud optical thickness, particle size
thermal infrared
(TIR) 		T1 10.8 μm 0.756 μm 250 m surface temperature of land, ocean, snow & ice. Fire detection, vegetation water stress
T2 12.0 μm 0.759 μm

See also edit

References edit

  1. ^ GCOM-W1 at NSSDC
  2. ^ GCOM-W at JAXA
  3. ^ "SHIZUKU Observation Data Acquired by AMSR2". JAXA. Retrieved 2 July 2014.
  4. ^ "JAXA: Global Change Observation Mission – Climate (GCOM-C)". Retrieved 2 July 2014.

April 30, 2024
global, change, observation, mission, gcom, jaxa, project, long, term, observation, earth, environmental, changes, part, japan, contributions, geoss, global, earth, observation, system, systems, gcom, will, continued, years, with, observation, utilization, glo. GCOM Global Change Observation Mission is a JAXA project of long term observation of Earth environmental changes As a part of Japan s contributions to GEOSS Global Earth Observation System of Systems GCOM will be continued for 10 to 15 years with observation and utilization of global geophysical data such as precipitation snow water vapor aerosol for climate change prediction water management and food security On May 18 2012 the first satellite GCOM W nickname Shizuku was launched On December 23 2017 the second satellite GCOM C1 nickname Shikisai was launched An artist s rendering of GCOM W1 Contents 1 GCOM W 2 GCOM C1 3 Sensors 3 1 AMSR2 3 2 SGLI 4 See also 5 ReferencesGCOM W edit nbsp Launch of GCOM W aboard a H IIA rocket GCOM W Global Change Observation Mission Water nickname Shizuku is the first in the GCOM series Its mission is to observe the water cycle The satellite carries the AMSR2 Advanced Microwave Scanning Radiometer 2 instrument the successor to the AMSR E carried by Aqua This microwave radiometer will observe precipitation water vapor wind velocity above the ocean sea water temperature water levels on land areas and snow depths GCOM W was approved in 2006 and development of the satellite started in 2007 with a mission budget of 20 billion Yen US 200 Million Mass of the satellite is 1990 kg 1 2 Planned lifespan is 5 years Polar orbit altitude 700 km with equator crossing local time on the ascending orbit is 13 30PM 00 15 GCOM W was launched on May 17 2012 via a H IIA rocket and it flies in a Sun synchronous orbit as part of the A train satellite constellation It successfully began collecting data on July 4 2012 Its planned lifespan of 5 years means that the satellite is set to operate until 2017 although JAXA hopes that it will last longer 3 GCOM C1 editGCOM C1 Global Change Observation Mission Climate nickname Shikisai the first satellite in the GCOM C series will monitor global climate change by observing the surface and atmosphere of Earth over the course of 5 years Through use of its SGLI Second generation GLobal Imager optical instrument it will collect data related to the carbon cycle and radiation budget such as measurements of clouds aerosols ocean color vegetation and snow and ice From its Sun synchronous orbit altitude 798 km SGLI will collect a complete picture of Earth every 2 3 days with a resolution of 250 1000m across the UV visible and infrared spectrums Mass of the satellite is 2020 kg 4 Equator crossing local time on the descending orbit is 10 30AM 00 15 GCOM C was launched on December 23 2017 via a H IIA rocket Sensors editAMSR2 edit AMSR2 Advanced Microwave Scanning Radiometer 2 is an improved version of AMSR aperture 2 0 m on ADEOS II and AMSR E aperture 1 6 m on NASA s Aqua satellite By rotating a disc antenna diameter 2 0 m in 1 5 s period it scans the Earth surface along an arc of 1450 km length Reliability is better than AMSR and AMSR E Planned lifetime has been extended from 3 years to 5 years A new microwave band namely 7 3 GHz has been added The 7 3 GHz band is for duplication and calibration of 6 925 GHz band AMSR2 continues the legacy of AMSR E which also observed as part of the A Train constellation AMSR2 observation frequency parameter frequency GHz 6 925 7 3 10 65 18 7 23 8 36 5 89 0 comments column vapor column precipitable water precipitation sea surface temperature sea surface wind speed sea ice density 89 GHz is only for cloudless area snowpack soil moisture Note means the most important band for that purpose SGLI edit SGLI Second generation Global Imager is a multi band optical radiometer and the successor of GLI sensor on ADEOS II It consists of two sensors SGLI VNR an electronic scan and SGLI IRS a mechanical scan SGLI VNR succeeds the technology of MESSR on MOS 1 OPS VNIR on JERS 1 AVNIR on ADEOS and AVNIR 2 on ALOS The number of channels of SGLI is 19 which is much less than GLI 36 channels This is because SGLI carefully selected the essential bands for observations The swath size is 1150 km for SGLI VNR and 1400 km for SGLI IRS Although a little reduction from GLI all channels were mechanical scan with 1400 km swath it has more bands with high resolution 250 m Polarimetry function has been added to SGLI VNR which helps detection of size of aerosol particles enabling detection of source of the aerosols The lesson of GLI sensor s too big and too complicated structure SGLI is divided to two simple systems and the number of channels have been minimized to really essential bands aiming at better reliability and survivability SGLI observation channels instruments channel central wavelength bandwidth resolution target SGLI VNR non polarization VN1 380 nm 10 6 nm 250 m terrestrial aerosol atmospheric correction ocean color snow and ice VN2 412 nm 10 3 nm vegetation terrestrial aerosol atmospheric correction oceanic aerosol photosynthetic active radiation snow and ice VN3 443 nm 10 1 nm vegetation oceanic aerosol atmospheric correction photosynthetic active radiation ocean color snow and ice VN4 490 nm 10 3 nm ocean color chlorophyll suspended sediments VN5 530 nm 19 1 nm photosynthetic active radiation ocean color chlorophyll VN6 565 nm 19 8 nm ocean color chlorophyll suspended sediments colored dissolved organic matters VN7 673 5 nm 22 nm vegetation terrestrial aerosol atmospheric correction ocean color VN8 673 5 nm 21 9 nm VN9 763 nm 11 4 nm 1000 m liquid cloud geometric thickness VN10 868 5 nm 20 9 nm 250 m vegetation terrestrial aerosol atmospheric correction ocean color snow and ice VN11 868 5 nm 20 8 nm polarization P1 673 5 nm 20 6 nm 1000 m vegetation terrestrial aerosol atmospheric correction ocean color P2 868 5 nm 20 3 nm vegetation terrestrial aerosol atmospheric correction ocean color snow and ice SGLI IRS short wave infrared SWIR SW1 1050 nm 21 1 nm 1000 m liquid cloud optical thickness particle size SW2 1380 nm 20 1 nm detection of clouds over snow and ice SW3 1630 nm 195 nm 250 m SW4 2210 nm 50 4 nm 1000 m liquid cloud optical thickness particle size thermal infrared TIR T1 10 8 mm 0 756 mm 250 m surface temperature of land ocean snow amp ice Fire detection vegetation water stress T2 12 0 mm 0 759 mmSee also editADEOS Midori ADEOS II Midori II A train GEOSS GOSAT Ibuki Sentinel programmeReferences edit GCOM W1 at NSSDC GCOM W at JAXA SHIZUKU Observation Data Acquired by AMSR2 JAXA Retrieved 2 July 2014 JAXA Global Change Observation Mission Climate GCOM C Retrieved 2 July 2014 Retrieved from https en wikipedia org w index php title Global Change Observation Mission amp oldid 1191272367 GCOM W, wikipedia, wiki, book, books, library,

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