NOAA Center for Satellite Applications and Research banner
 
Intranet • Contact • Skip navigation
National Oceanographic & Atmospheric Administration website NOAA Center for Satellite Applications and Research website

MiRS Sensors
Megha-Tropiques SAPHIR Overview

SAPHIR schematic

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)

Scan pattern of the SAPHIR instrument



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

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



Notes:

Source: MEGHA-TROPIQUES Home

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