Faraday Rotation

David Le VineAquarius Algorithm Workshop

March 9-11, 2010

Approach

Rotation Angle Retrieved from 3rd Stokes Parameter*: ΩF = 0.5 Atan[ T3 / (Tv – Th) ]

*S. Yueh, “Estimation of Faraday Rotation with Passive Microwave Polarimetry for Microwave Remote Sensing of Earth Surfaces”, TGARS, Vol 38 (#5), pp. 2434, Sept. 2000.

Example: Aquarius Simulator

Antenna temperature for vertical polarization (top), horizontal polarization (middle) and third Stokes parameter (bottom) for the Aquarius middle beam.

Retrieved Faraday Rotation Angle

(Top) Faraday rotation angle at boresight of the middle radiometer beam. (Bottom) Third Stokes parameter for the same antenna.

Plan• Test – SMOS “full-pol” data

• Remove spurious signals– Filter at land/water boundaries– Match to theoretical profile

• Magnetic field + estimate of TEC

• Remove bias– Match ground truth (sounder) at selected locations

• Backup Plan– Use model (data assimilation)– Correct for altitude (SMOS algorithm)

Retrieved Faraday Rotation Angle

(Top) Faraday rotation angle at boresight of the middle radiometer beam. (Bottom) Third Stokes parameter for the same antenna.

Rotation Angle Retrieved from 3rd Stokes Parameter*: ΩF = 0.5 Atan[ T3 / (Tv – Th) ]

*S. Yueh, “Estimation of Faraday Rotation with Passive Microwave Polarimetry for Microwave Remote Sensing of Earth Surfaces”, TGARS, Vol 38 (#5), pp. 2434, Sept. 2000.