The Influence of Antenna Pattern on Faraday Rotation in Remote Sensing at L-Band

The influence of the pattern of the receive antenna on measured Faraday rotation is examined in the context of passive remote sensing of soil moisture and ocean salinity at L-band. Faraday rotation is an important consideration for radiometers on future missions in space, such as SMOS and Aquarius. Using the radiometer on Aquarius as an example, it is shown that, while I = Tv + Th is independent of Faraday rotation to first order, it has rotation dependence when realistic antenna patterns are included in the analysis. In addition, it is shown that using the third Stokes parameter to measure the rotation angle can yield a result that is biased by as much as 1deg by purely geometrical issues that are associated with the finite width of the main beam.

[1]  Simon Yueh,et al.  Estimates of Faraday rotation with passive microwave polarimetry for microwave remote sensing of Earth surfaces , 2000, IEEE Trans. Geosci. Remote. Sens..

[2]  S. Yueh,et al.  Aquarius: A Mission to Monitor Sea Surface Salinity from Space , 2006, 2006 IEEE MicroRad.

[3]  Simon Yueh,et al.  Aquarius/SAC-D mission overview , 2006, SPIE Remote Sensing.

[4]  J. Kong,et al.  Theory of microwave remote sensing , 1985 .

[5]  Manuel Martín-Neira,et al.  Faraday rotation correction in the polarimetric mode of MIRAS , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[6]  Gary S. E. Lagerloef,et al.  Sea Surface Salinity: The Next Remote Sensing Challenge , 1995 .

[7]  Bodo W. Reinisch,et al.  International Reference Ionosphere 2000 , 2001 .

[8]  C. E. Barton,et al.  International Geomagnetic Reference Field : The seventh generation , 1997 .

[9]  Yann Kerr,et al.  The Soil Moisture and Ocean Salinity Mission - An Overview , 2008, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium.

[10]  Thomas Meissner,et al.  Polarization rotation and the third Stokes parameter: the effects of spacecraft attitude and Faraday rotation , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[11]  David M. Le Vine,et al.  Effects of the Antenna Aperture on Remote Sensing of Sea Surface Salinity at L-band. , 2007, 2006 IEEE MicroRad.

[12]  David M. Le Vine,et al.  Aquarius: An Instrument to Monitor Sea Surface Salinity From Space , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[13]  David M. Le Vine,et al.  The effect of the ionosphere on remote sensing of sea surface salinity from space: absorption and emission at L band , 2002, IEEE Trans. Geosci. Remote. Sens..

[14]  Yann Kerr,et al.  Soil moisture retrieval from space: the Soil Moisture and Ocean Salinity (SMOS) mission , 2001, IEEE Trans. Geosci. Remote. Sens..

[15]  A. Fung.  Microwave Scattering and Emission Models and their Applications , 1994 .

[16]  Saji Abraham,et al.  Evaluation of IRI-95 to correct errors caused by faraday rotation in passive microwave remote sensing from space , 2001 .

[17]  A. Ludwig.  The definition of cross polarization , 1973 .

[18]  Adriano Camps,et al.  Polarimetric formulation of the visibility function equation including cross-polar antenna patterns , 2005, IEEE Geoscience and Remote Sensing Letters.

[19]  G. Swenson,et al.  Interferometry and Synthesis in Radio Astronomy , 1986 .