BackForwardInstrument:  OCO (ISS) spectrometer 

Instrument details
Acronym OCO (ISS) spectrometer
Full name Orbiting Carbon Observatory ISS spectrometer
Purpose CO2 profile
Short description 3 NIR/SWIR grating spectrometer, 3 bands, 0.76 µm (O2), 1.61 and 2.06 µm (CO2) - 3000 channels total [see detailed characteristics below]
Background Follow-on of OCO flown on OCO-2. Now flown on the International Space Station
Scanning Technique Pushbroom, cross-track swath 10 km, 160 pixels/line binned to 10 super-pixels/line. Three pointing modes: nadir, towards sun glint and towards a specific target
Resolution 1.29 km (cross-track), 2.25 km (along-track)
Coverage / Cycle Latitude-limited by the orbital inclination of the ISS (51.6°): low and middle latitudes covered nearly daily.
Mass 150 kg Power 165 W Data Rate 1 Mbps


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2019 to 2026
Last update: 2024-01-22
Detailed characteristics

Spectral range

No. of channels

Spectral resolution

SNR @ specified input spectral radiance

758-772 nm


0.04 nm

…….. @ ……… W m-2 sr-1 μm-1

1594-1619 nm


0.08 nm

…….. @ ……… W m-2 sr-1 μm-1

2042-2082 nm


0.10 nm

…….. @ ……… W m-2 sr-1 μm-1

Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Earth observation instrument
  • Passive optical radiometer or spectrometer
  • Cross-nadir shortwave (UV/VIS) sounder
WIGOS Subcomponents
  • Subcomponent 1
  • UV/VIS/NIR sounders, nadir and limb
  • UV/VIS/NIR nadir sounder
  • Subcomponent 2
  • NIR/SWIR imaging spectroscopy
  • NIR/SWIR imaging spectrometer
  • Subcomponent 3
  • NIR spectrometer
  • NIR spectrometer
Mission objectives
Primary mission objectives
  • CO2
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
CO2*1 - primaryCloud sensitive.. Daylight only.Very-high resolution SWIR spectrometry CO2 lines around 1.6 and 2.1 micrometers. Specifically designed for CO2.