BackForwardInstrument:  SSMIS 

Instrument details
Acronym SSMIS
Full name Special Sensor Microwave - Imager/Sounder
Type of Instrument 08. MW imaging/sounding radiometer, conical scanning
Purpose Multi-purpose imagery with temperature/humidity sounding channels for improved precipitation
Short description 21 frequencies, 24 channels MW radiometer covering the 54 and 183 GHz bands
Background Replacing and merging SSM/I, SSM/T and SSM/T-2 flown on DMSP up to F15
Scanning Technique Conical: 53.1° zenith angle, swath 1700 km – Scan rate: 31.9 scan/min = 12.5 km/scan
Resolution Changing with frequency, consistent with an antenna diameter of  61 x 66 cm
Coverage / Cycle Global coverage once/day
Mass 96 kg Power 135 W Data Rate 14.2 kbps

 

Providing Agency DoD
Instrument Maturity Flown on operational programme
Utilization Period: 2003-10-18 to ≥2025
Last update: 2012-09-14
Detailed characteristics
Central frequency (GHz) Bandwidth (MHz) Polarisations NEΔT IFOV Pixel
19.35 356 V, H 0.34 K 43.5 x73.6 km 25.0 x12.5 km
22.235 407 V 0.45 K 43.5 x73.6 km 25.0 x12.5 km
37.0 1580 V, H 0.24 K 43.5 x73.6 km 25.0 x12.5 km
50.3 380 H 0.21 K 37.7 x38.8 km 37.5 x12.5 km
52.8 389 H 0.20 K 37.7 x38.8 km 37.5 x12.5 km
53.596 380 H 0.21 K 37.7 x38.8 km 37.5 x12.5 km
54.4 382 H 0.20 K 37.7 x38.8 km 37.5 x12.5 km
55.5 391 H 0.22 K 37.7 x38.8 km 37.5 x12.5 km
57.29 330 RC 0.26 K 37.7 x38.8 km 37.5 x12.5 km
59.4 239 RC 0.25 K 37.7 x38.8 km 37.5 x12.5 km
60.792668 ± 0.357892 ± 0.050 106 RC 0.38 K 72.5 x75.0 km 75.0 x12.5 km
60.792668 ± 0.357892 ± 0.016 29.4 RC 0.37 K 72.5 x75.0 km 75.0 x12.5 km
60.792668 ± 0.357892 ± 0.006 10.4 RC 0.58 K 72.5 x75.0 km 75.0 x12.5 km
60.792668 ± 0.357892 ± 0.002 5.2 RC 0.86 K 72.5 x75.0 km 75.0 x12.5 km
60.792668 ± 0.357892 2.7 RC 1.18 K 72.5 x75.0 km 75.0 x12.5 km
63.283248 ± 0.285271 2.7 RC 1.23 K 72.5 x75.0 km 75.0 x12.5 km
91.655 2829 V, H 0.19 K 13.2 x15.5 km 12.5 x12.5 km
150 3284 H 0.53 K 13.2 x15.5 km 12.5 x12.5 km
183.31 ± 6.6 1025 H 0.56 K 13.2 x15.5 km 12.5 x12.5 km
183.31 ± 3.0 2038 H 0.39 K 13.2 x15.5 km 12.5 x12.5 km
183.31 ± 1.0 3052 H 0.38 K 13.2 x15.5 km 12.5 x12.5 km
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

Contribution to Space Capabilities

The instrument contributes to the following Capabilities, as identified in the "Vision for the GOS in 2025" and the Implementation Plan for the Evolution of Global Observing Systems:

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.
Variable Relevance for measuring this Variable Operational Limitations Processing maturity
Cloud liquid water (CLW) total column 2-very high No specific limitation Consolidated methodology
Snow cover 3-high Snow-depth dependent Consolidated methodology
Cloud liquid water (CLW) 3-high Highly indirect Heavily model-dependent
Cloud ice (total column) 3-high No specific limitation Consolidated methodology
Snow water equivalent 4-fair Snow-depth dependent Heavily dependent on external info
Snow status (wet/dry) 4-fair Snow-depth dependent Consolidated methodology
Integrated Water Vapour (IWV) 4-fair No specific limitation Consolidated methodology
Atmospheric temperature 4-fair Coarse vertical resolution Consolidated methodology
Specific humidity 4-fair Coarse vertical resolution Consolidated methodology
Cloud ice effective radius 4-fair Highly indirect Heavily model-dependent
Sea-ice cover 4-fair Coarse resolution Consolidated methodology
Cloud ice 4-fair Highly indirect Heavily model-dependent
Accumulated precipitation (over 24 h) 4-fair Highly indirect Heavily dependent on external info
Precipitation intensity at surface (liquid or solid) 4-fair Highly indirect Heavily model-dependent
Wind speed over the surface (horizontal) 4-fair Only over sea Consolidated methodology
Cloud drop effective radius 5-marginal Highly indirect Heavily model-dependent
Freezing level height in clouds 5-marginal Highly indirect Heavily model-dependent
Melting layer depth in clouds 5-marginal Highly indirect Heavily model-dependent
Upward long-wave irradiance at Earth surface 5-marginal Highly indirect Heavily dependent on external info