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Instrument Descriptions
- AMSU-A
- MHS
- SSMIS
- WindSat
- AMSR-E
- AMSR-2
- SNPP ATMS
- TRMM TMI
- GPM GMI
- Megha-Tropiques MADRAS
- Megha-Tropiques SAPHIR

Algorithm

Product Monitoring

Radiometric Performance
- TB Comparison
- Radiometric Bias Monitoring

Geophysical Performance
- Geophysical Performance Monitoring
- Performance Time Series

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MiRS Sensors
Megha-Tropiques SAPHIR Overview

SAPHIR schematic

Satellite(s)

Megha-Tropiques

MiRS Production Status

Operational.

SAPHIR is a sounding instrument with 6 channels near the absorption band of water vapor at 183 Ghz. These channels provide relatively narrow weighting functions from the surface to about 10 km, allowing retrieving water vapor profiles in the cloud free troposphere. The scanning is cross- track, up to an incidence angle of 50°. The resolution at nadir is of 10 km.

SAPHIR channel specification
Channel	Central Frequency (GHz)	Bandwidth (MHz)	NE∆T	Polarization	Interchannel calibration
S1	183.31±0.20	200	2.35 K	H	0.5K
S2	183.31±1.10	350	1.45 K	H	0.5K
S3	183.31±2.80	500	1.36 K	H	0.5K
S4	183.31±4.20	700	1.38 K	H	0.5K
S5	183.31±6.80	1200	1.03 K	H	0.5K
S6	183.31±11.0	200	1.10 K	H	0.5K

Scan pattern of the SAPHIR instrument (image credit: CNES)

The 6 channels of SAPHIR positioned versus the water vapour absorption line at 183.31 Ghz

Notes:

Source: MEGHA-TROPIQUES Home

Source: MEGHA-TROPIQUES @ eoPortal

Photo: Photo of the MADRAS instrument under thermo-VAC test.

Vertical polarization
Horizontal polarization
Left-hand circular polarization (LHCP), also known as CCW (Counter Clock-wise)
Right-hand circular polarization (RHCP), also known as CW (Clock-wise)

MiRS Sensors Megha-Tropiques SAPHIR Overview