BackForwardInstrument:  MATHS 

Instrument details
Acronym MATHS
Full name Millimetre wave Atmospheric Temperature and Humidity Sounder
Purpose Temperature and Humidity sounding in almost all-weather conditions.  Also precipitation rate.
Short description

A 20-channel cross-track scanning Radiometer operating at 50-60 GHz and 183.31± 16.25GHz bands. See table below.
Background

A new development
Scanning Technique

Cross-track scanning. 
Resolution Temperature sounding channels have nadir spatial resolution of 25 km. Humidity sounding channels 15 km.
Coverage / Cycle Near-global coverage twice/day. 1565 swath width.
Mass 78 kg Power 111 W Data Rate 135

 

Providing Agency ISRO
Instrument Maturity Flown on operational programme
Utilization Period: 2026 to 2030
Last update: 2026-03-30
Detailed characteristics
Number Frequency (GHz) Bandwidth (MHz) IFOV (km) Polarisation NeDT (K)
1 50.53 300 25 QH 0.5
2 51.76 300 25 QH 0.5
3 52.9

300

 25 QH 0.4
4 53.63 300 25 QH 0.4
5 54.4 300 25 QH 0.4
6 54.95 300 25 QH 0.4
7 55.5 300 25 QH 0.4
8 56.65 300 25 QH 0.4
9 57.545 100 25 QH 0.8
10 58.8 300 25 QH 0.4
11 59.38 240 25 QH 0.5
12 56.95 20 25 QH 1.5
13 59.6 10 25 QH 2.25
14 58.316 5 25 QH 3.2
15 183.31±1 500 15 QH 0.9
16 183.31±1.8 1000 15 QH 0.65
17 183.31±3 1000 15 QH 0.65
18 183.31±4.5 2000 15 QH 0.45
19 183.31±7 2000 15 QH 0.45
20 183.31±15.75 3000 15 QH 0.4
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 microwave radiometer
  • Cross-track, special or non-scanning microwave radiometer
WIGOS Subcomponents
  • Subcomponent 1
  • MW sounders [in SSO]
  • MW sounder [in SSO]
Mission objectives
Primary mission objectives
  • Atmospheric temperature
  • Specific humidity
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
Cloud drop effective radius5 - marginalHighly indirect.MW channels around 90 GHz, and in 183 GHz band
Cloud ice3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud ice Total Column3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud ice effective radius3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud liquid water (CLW)3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Cloud liquid water (CLW) total column3 - highNo specific limitation.MW channels around 90 GHz, and in 183 GHz band
Downward long-wave irradiance at Earth surface5 - marginalHighly indirect.MW channels in 183 GHz band to account for downward cloud radiation
Precipitation intensity at surface (liquid or solid)5 - marginalNo specific limitation.MW channels in the 183 GHz band. Suitable for solid precipitation over sea and land, Insensitive to surface emissivity
Specific humidity*3 - highCoarse vertical resolution.MW channels in the 183 GHz band
Integrated Water Vapour (IWV)2 - very highNo specific limitation.MW channels in the water vapour band around 183 GHz
Upward long-wave irradiance at Earth surface5 - marginalHighly indirect.MW channels is the 183 GHz band to infer the impact of clouds on the upward LW radiation