BackForwardInstrument:  IASI-NG 

Instrument details
Acronym IASI-NG
Full name Infrared Atmospheric Sounder Interferometer - New Generation
Purpose Temperature/humidity sounding, ozone profile and total-column or profiles of green-house gases (C2H2, C2H4, C2H6, CFC-11, CFC-12, CH3OH, CH4, CO, H2CO2, HCN, HNO2, HNO3, N2O, NH3, PAN, SO2)
Short description

16,921 channels, range 645-2760 cm-1 (3.62-15.50 μm) split in 12 bands [see detailed characteristics below]. Spectral resolution 0.125 cm-1 (unapodised)

Monitoring and calibration information here
Background

Evolution of IASI on Metop A, Metop-B, Metop-C
Scanning Technique

Cross-track: 16 steps of 100 km (14 earth-viewing FOV’s, one for cold space, one for blackbody) step-and-dwell scanned, for a swath of 2000 km. Along-track: one scan line every 100 km every 16 s.
Resolution 4 x 4 12-km IFOV’s regularly spread within the 100 x 100 km2 FOV (average sampling distance: 24 km).
Coverage / Cycle Near-global coverage twice/day
Mass 360 kg Power 500 W Data Rate 6 Mbps

 

Providing Agency CNES
Instrument Maturity Backed by strong heritage
Utilization Period: 2025 to 2047
Last update: 2024-09-23
Detailed characteristics

Band

Wavelength

Wavenumber

NEΔT after apodisation

IAS-1

15.50 μm

15.27 μm

15.08 μm

14.49 μm

645 cm-1

655 cm-1

663 cm-1

690 cm-1

0.39 K @ 280 K

0.26 K @ 280 K

0.225 K @ 280 K

0.225 K @ 280 K

IAS-2

12.99-14.49 μm

690-770 cm-1

0.130 K @ 280 K

IAS-3

10.00-12.99 μm

770-1000 cm-1

0.130 K @ 280 K

IAS-4

9.35-10.00 μm

1000-1070 cm-1

0.195 K @ 280 K

IAS-5

8.70-10.00 μm

1070-1150 cm-1

0.195 K @ 280 K

IAS-6

6.06-8.70 μm

1150-1650 cm-1

0.130 K @ 280 K

IAS-7

4.76-6.06 μm

1650-2100 cm-1

0.449 K @ 280 K

IAS-8

4.59-4.76 μm

2100-2180 cm-1

0.156 K @ 280 K

IAS-9

4.44-4.59 μm

2180-2250 cm-1

0.26 K @ 280 K

IAS-10

4.13-4.44 μm

2250-2420 cm-1

0.26 K @ 280 K

IAS-11

4.13 μm

4.08 μm

3.85 μm

3.70 μm

2420 cm-1

2450 cm-1

2600 cm-1

2700 cm-1

0.26 K @ 280 K

0.26 K @ 280 K

0.65 K @ 280 K

1.138 K @ 280 K

IAS-12

3.70 μm

3.62 μm

2700 cm-1

2760 cm-1

1.138 K @ 280 K

1.43 K @ 280 K
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 infrared sounder, possibly including VIS channels
WIGOS Subcomponents
  • Subcomponent 1
  • IR hyperspectral sounders [in SSO]
  • IR hyperspectral sounder [in SSO]
Mission objectives
Primary mission objectives
  • Atmospheric temperature
  • Height of the top of PBL
  • Height of the tropopause
  • Integrated Water Vapour (IWV)
  • O3 Total Column
  • Specific humidity
  • Temperature of the tropopause
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
Atmospheric temperature*1 - primaryCloud sensitive.MWIR and TIR spectrometry in the CO2 4.3 and 15 micrometer bands
C2H21 - primaryCloud sensitive.TIR spectrometry. C2H2 lines around 7.5 and 13.7 micrometers
C2H62 - very highCloud sensitive.TIR spectrometry. C2H6 lines around 12 micrometers
CFC-111 - primaryCloud sensitive.. Coarse vertical resolution.TIR spectrometry. CFC-11 lines around 9.2 and 11.7 micrometers
CFC-121 - primaryCloud sensitive.TIR spectrometry. CFC-12 lines around 8.8 and 10.8 micrometers
HCFC-221 - primaryCloud sensitive.TIR spectrometry. HCFC-22 lines around 7.6, 9.0 and 12.3 micrometers
CH3Br1 - primaryCloud sensitive.Spectrometry in the HC3Br bands around 6.7, 7.9 and 10.5 micrometers
CH4 mole fraction2 - very highCloud sensitive.MWIR and TIR spectrometry. CH4 lines around 3.4, 4.3 and 7.7 micrometers
ClONO21 - primaryCloud sensitive.MWIR and TIR spectrometry. ClONO2 lines around 5.7, 7.7 and 12.5 micrometers
Cloud cover3 - highDiscontinuous coverage.MWIR and TIR spectrometry
Cloud top height2 - very highDiscontinuous coverage.MWIR and TIR spectrometry in window and water vapour band (for emissivity) to estimate cloud top height from its temperature
Cloud top temperature1 - primaryDiscontinuous coverage.TIR spectrometry in window and water vapour band (for emissivity)
Cloud type4 - fairDiscontinuous coverage.MWIR and TIR spectrometry
CO3 - highCloud sensitive.MWIR spectrometry. CO lines around 4.6 micrometers
CO2 mole fraction2 - very highCloud sensitive.MWIR and TIR spectrometry. CO2 lines around 4.3 and 15 micrometers
COS1 - primaryCloud sensitive.MWIR and TIR spectrometry. COS lines around 4.8 and 11.6 micrometers
Downward long-wave irradiance at Earth surface1 - primaryCloud sensitive.. Highly indirect.MWIR and TIR spectrometry including water vapour and CO2 bands
H2O1 - primaryCloud sensitive.MWIR/TIR spectrometry in a range centred on 6.3 micrometers
Height of the top of PBL*3 - highCloud sensitive.MWIR and TIR spectrometry. Height of PBL top from temperature profile
Height of the tropopause*3 - highCloud sensitive.TIR spectrometry. Height of tropopause from temperature profile
HNO31 - primaryCloud sensitive.. Coarse vertical resolution.MWIR and TIR spectrometry. HNO3 lines around 5.9, 7.6 and 11.3 micrometers
Land surface temperature2 - very highCloud sensitive.. Coarse spatial resolution.MWIR and TIR spectrometry (inclusive of several narrow-bandwidth windows and absorption bands for atmospheric corrections)
Long-wave Earth surface emissivity1 - primaryCloud sensitive.. Long time series needed.MWIR and TIR spectrometry measuring land temperature in many windows. Emissivity inferred by statistical analysis
N2O mole fraction2 - very highCloud sensitive.MWIR and TIR spectrometry. N2O lines around 4.5 and 7.7 micrometers
N2O51 - primaryCloud sensitive.MWIR and TIR spectrometry. N2O5 lines around 5.8 and 8 micrometers
NO1 - primaryCloud sensitive.MWIR spectrometry. NO lines around 5.3 micrometers
NO23 - highCloud sensitive.TIR spectrometry. NO2 lines around 6.1 micrometers
NO2 Total Column1 - primaryCloud sensitive.TIR spectrometry. NO2 lines around 6.1 micrometers
O33 - highCloud sensitive.TIR spectrometry. Ozone band around 9.7 micrometers
O3 Total Column*3 - highCloud sensitive.TIR channel(s). Ozone lines in band around 9.7 micrometers
PAN1 - primaryCloud sensitive.MWIR and TIR spectrometry. PAN lines around 5.7, 8.6 and 12.5 micrometers
PSC occurrence2 - very highCoarse vertical resolution.MWIR and TIR spectroscopy
Sea surface temperature1 - primaryCloud sensitive.MWIR and TIR spectrometry (inclusive of several narrow-bandwidth windows and absorption bands for atmospheric corrections)
SF61 - primaryCloud sensitive.TIR spectrometry. SF6 lines around 10.5 micrometers
SO21 - primaryCloud sensitive.TIR spectrometry. SO2 lines around 7.3 and 8.6 micrometers
SO2 Total Column1 - primaryCloud sensitive.TIR spectrometry. SO2 lines around 7.3 and 8.6 micrometers
Specific humidity*1 - primaryCloud sensitive.TIR spectrometry in the water vapour band around 6.3 micrometers
Integrated Water Vapour (IWV)*2 - very highCloud sensitive.TIR spectrometry in the bands around 6.3 and above 11 micrometers
Temperature of the tropopause*2 - very highCloud sensitive.TIR spectrometry. Tropopause temperature from temperature profile
Upward spectral radiance at TOA2 - very highMissing all Short-waves.MWIR and TIR spectrometry resolving water vapour lines in the bands around 6.3 micrometers and 11 to 15 micrometers; and other greenhouse gases
Upward long-wave irradiance at TOA3 - highSpectral interpolation needed.MWIR and TIR spectrometry in the windows regions around 3.7 and 11 micrometers, and in water vapour and CO2 bands around 4,3, 6.3 and 15 micrometers
Upward long-wave irradiance at Earth surface1 - primaryCloud sensitive.. Highly indirect.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in water vapour and CO2 bands around 4,3, 6.3 and 15 micrometers
Wind (horizontal)3 - highLimited to high latitudes.. Cloud sensitive.TIR spectrometry in the 6.3 micrometers band. Wind profile in clear air by tracking water vapour patches in the humidity profile