BackForwardInstrument:  SOUNDER (INSAT) 

Instrument details
Acronym SOUNDER (INSAT)
Full name INSAT Sounder
Purpose Temperature/humidity sounding
Short description 19 channels (including one VIS) [see detailed characteristics below]
Background New development
Scanning Technique Mechanical, bi-axial, 3-axis stabilised satellite, step-and-dwell
Resolution 10 km
Coverage / Cycle 6400 km x 6400 km2 in 3 h.  Smaller areas in correspondingly shorter time intervals
Mass 147 kg Power 76 W Data Rate 40 kbps

 

Providing Agency ISRO
Instrument Maturity Backed by strong heritage
Utilization Period: 2014-01-15 to ≥2029
Last update: 2017-03-29
Detailed characteristics
Wavelength Wave number Bandwidth SNR or NEΔT @ specified input
14.67 µm 682 cm-1 13 cm-1 0.17 K @ 300 K
14.32 µm 699 cm-1 13 cm-1 0.16 K @ 300 K
14.04 µm 712 cm-1 13 cm-1 0.15 K @ 300 K
13.64 µm 733 cm-1 16 cm-1 0.12 K @ 300 K
13.32 µm 751 cm-1 16 cm-1 0.12 K @ 300 K
12.62 µm 793 cm-1 30 cm-1 0.07 K @ 300 K
11.99 µm 834 cm-1 50 cm-1 0.05 K @ 300 K
11.04 µm 906 cm-1 50 cm-1 0.05 K @ 300 K
9.72 µm 1029 cm-1 25 cm-1 0.10 K @ 300 K
7.44 µm 1344 cm-1 55 cm-1 0.05 K @ 300 K
7.03 µm 1422 cm-1 80 cm-1 0.05 K @ 300 K
6.53 µm 1531 cm-1 60 cm-1 0.10 K @ 300 K
4.58 µm 2184 cm-1 23 cm-1 0.05 K @ 300 K
4.53 µm 2209 cm-1 23 cm-1 0.05 K @ 300 K
4.46 µm 2241 cm-1 23 cm-1 0.05 K @ 300 K
4.13 µm 2420 cm-1 40 cm-1 0.05 K @ 300 K
3.98 µm 2510 cm-1 40 cm-1 0.05 K @ 300 K
3.76 µm 2658 cm-1 100 cm-1 0.05 K @ 300 K
0.695 µm 14367 cm-1 0.05 µm 1800 @ 100 % albedo
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
Mission objectives
Primary mission objectives
  • Atmospheric temperature
  • Integrated Water Vapour (IWV)
  • Specific humidity
Secondary mission objectives
  • Sea surface temperature
Opportunity objectives
  • Cloud cover
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Tentative 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
VariableRelevance for measuring this variableOperational limitationsExplanation
Atmospheric temperature3 - highCloud sensitive.. Coarse vertical resolution.Several MWIR and TIR channels in the 4.3 and 15 micrometer bands. Frequent sampling (GEO) enables monitoring instability onset
Cloud cover4 - fairDiscontinuous coverage.MWIR and TIR channels
Cloud top height2 - very highDiscontinuous coverage.TIR channels in window and water vapour band (for emissivity) for temperature; and in CO2 band for atmospheric column above cloud top
Cloud top temperature2 - very highDiscontinuous coverage.TIR channels in window and water vapour band (for emissivity)
Cloud type4 - fairDiscontinuous coverage.MWIR and TIR channels
Downward long-wave irradiance at Earth surface3 - highCloud sensitive.. Highly indirect.MWIR and TIR channels including water vapour and CO2 bands
Land surface temperature3 - highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels in windows and absorption bands for atmospheric corrections
O3 Total Column5 - marginalCloud sensitive.TIR channel(s). Ozone lines in band around 9.7 micrometers. Frequent sampling (GEO) enables monitoring diurnal variations
Sea surface temperature2 - very highCloud sensitive.MWIR and TIR window channels (cloud impact reduction, water vapour correction)
Specific humidity3 - highCloud sensitive.. Very coarse vertical resolution.. Middle troposphere only.TIR channels in the water vapour band around 6.3 micrometers
Integrated Water Vapour (IWV)3 - highCloud sensitive.. Inaccurate in high troposphere.TIR channels around 6.3 micrometers and in the 11 micrometers split window
Upward long-wave irradiance at TOA4 - fairSpectral interpolation needed.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
Upward long-wave irradiance at Earth surface3 - highCloud 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