Filter Wedge Spectrometer
Temperature and humidity sounding in bands SWIR and MWIR
Spectral scanning by alternating filters placed on the border of a wheel. Two bands, 3.2-6.4 μm and 1.2-2.4 μm; spectral resolution 0.6-1.2 %
Prototype of filter radiometers still in use, for instance the current HIRS of POES and MetOp.
Non-scanning. Nadir viewing only
70 km s.s.p.
Coverage / Cycle
Global in 20 days for the MWIR band, 40 days for the SWIR band
Flown on an R&D satellite
1970 to 1980-09-30
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
Earth observation instrument Passive optical radiometer or spectrometer Cross-nadir infrared sounder, possibly including VIS channels
No WIGOS subcomponents have been defined.
Tentative Evaluation of Measurements
The following list indicates which measurements can
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 Explanation
Atmospheric temperature 2 - very high Cloud sensitive.. Inaccurate in high troposphere.. Night time only.. Along-track only. MWIR spectrometry in the CO2 band around 4.3 micrometers
Specific humidity 3 - high Cloud sensitive.. Very coarse vertical resolution.. Middle troposphere only.. Along-track only. TIR channels in the water vapour band around 6.3 micrometers