Sensor · Spaceborne

Geostationary Environment Monitoring Spectrometer (GEMS)

Missions → GEO-KOMPSAT-2B (Operational)

Geostationary atmospheric-composition spectrometer flown on GEO-KOMPSAT-2B.

Sensor

Geostationary Environment Monitoring Spectrometer (GEMS) is an operational geostationary UV-visible hyperspectrometer on GEO-KOMPSAT-2B, launched in February 2020.^[1]^[2] It measures sulfur dioxide, nitrogen dioxide, ozone, formaldehyde, and aerosols over East and Southeast Asia from geostationary orbit.^[1] Its documented instrument class is a UV/VIS grating imaging spectrometer with a 300-500 nm range, spectral resolution below 0.6 nm, hourly daylight coverage over 5 S to 45 N and 75 E to 145 E, and 5 km resolution over Korea.^[2]

Tropospheric nitrogen dioxide and sulfur dioxide column retrieval is demonstrated on GEO-KOMPSAT-2B.^[1] Peer-reviewed validation work documents GEMS polarization characteristics and a correction algorithm, which matters for users evaluating radiometric stability and trace-gas retrieval quality in the UV-visible range.^[3] GEMS supports regional air-quality and atmospheric-composition monitoring that needs frequent daylight geostationary refresh over Asia rather than global polar-orbit coverage.^[1]^[2]

Operator pricing

Pricing not publicly listed by operator

Supply chain position

carried by GEO-KOMPSAT-2B

Methods this sensor implements

Demonstrated

UV-VIS nadir spectroscopyvia GEO-KOMPSAT-2B
GEMS demonstrates geostationary tropospheric column mapping for air-quality species on GEO-KOMPSAT-2B.

Capable, undemonstrated

None on record.

Topics this relates to

Air quality UV-VIS nadir spectroscopy(demonstrated)well suited

Shipping emissions UV-VIS nadir spectroscopy(demonstrated)well suited

Stratospheric ozone UV-VIS nadir spectroscopy(demonstrated)well suited

Geology and geohazards UV-VIS nadir spectroscopy(demonstrated)adequate

Industrial emissions UV-VIS nadir spectroscopy(demonstrated)adequate

Aerosol and cloud microphysical properties UV-VIS nadir spectroscopy(demonstrated)marginal

CO2 UV-VIS nadir spectroscopy(demonstrated)marginal

Sources

[1]Introduction to GEMS onboard GK-2Bagency doc2026-06-16
[2]WMO OSCAR instrument record: GEMSagency doc2026-06-16
[3]Geostationary Environment Monitoring Spectrometer (GEMS) polarization characteristics and correction algorithmpeer reviewed2026-06-16
[4]GEMS factsheetoperator datasheet2026-06-16

Cite https://eo-atlas.org/products/sensor/gems Markdown twin → Field definitions → Suggest a correction →

How to cite this page

Plain text

Geostationary Environment Monitoring Spectrometer (GEMS). EO-Atlas, SpectraWorks B.V. https://eo-atlas.org/products/sensor/gems (CC BY 4.0)

BibTeX

@misc{eoatlas:products:sensor:gems,
  title = {Geostationary Environment Monitoring Spectrometer (GEMS)},
  author = {{EO-Atlas}},
  publisher = {SpectraWorks B.V.},
  note = {CC BY 4.0},
  url = {https://eo-atlas.org/products/sensor/gems}
}