A Review of Polarization Orientation Estimation from Polarimetric SAR Data
4555 Overlook Ave. SW,
Washington DC 20375-5351,
Jong-Sen Lee, Dale L. Schuler, and Thomas L. Ainsworth
Division, Code 7263, Naval Research Laboratory, Washington DC 20375-5351
Author: Jong-Sen Lee
In recent studies, Schuler et al. applied
polarimetric SAR derived orientation angles to measure topography, and Lee et
al. used orientation angles for polarimetric SAR data compensation. The results
from this technique generally agree well with the DEM map. However, the
accuracy is not as good as that from SAR interferometry. Accurate estimation of
geophysical parameters, such as soil moisture, surface roughness, snow depth,
etc requires polarimetric SAR data to be compensated for terrain slope
variations. Many different techniques [1-4] for the estimation of orientation
angles have been proposed. However, in these studies, inconsistency in the
estimation of orientation angles was encountered in several areas, introducing
noisy and erroneous results. To support these applications, it is important to
accurately estimate shifts in orientation angles induced by the azimuth slope
variations. However, in many cases, inconsistency in the estimation of
orientation angle shifts was encountered in several areas, introducing noisy
and erroneous results. In this paper, we review estimation algorithms and
applications of polarization orientation angle induced by terrain slopes. We
develop a unified analysis of estimation algorithms based on the circular
polarization covariance matrix. The concept of reflection symmetry is used to
explain the soundness of the circular polarization method, and to show problems
associated with other algorithms. The relationship between several algorithms
will also be explored from different viewpoints, and a theoretical model will
be used to explain the results. The effect of radar frequency, scattering
media, and polarimetric calibration will also be discussed. SIR-C, and JPL
AIRSAR L- band and P-band polarimetric SAR images are used for demonstration.
 J.S. Lee, D.L. Schuler and T.L. Ainsworth, "Polarimetric SAR
Data Compensation for Terrain Azimuth Slope Variation," IEEE Transactions on
Geoscience and Remote Sensing, vol. 38, no. 5, 2153-2163, September 2000.
D.L. Schuler, J.S. Lee, G. De Grandi, "Measurement of Topography using
Polarimetric SAR Images," IEEE Trans. on Geoscience and Remote Sensing, no.5,
pp. 1266- 1277, 1996.
 D.L. Schuler, J.S. Lee, T.L. Ainsworth, and M.R.
Grunes, "Terrain Topography Measurement Using Multipass Polarimetric Synthetic
Aperture Radar Data," Radio Science, vol. 35, no.3, 813- 832, May-June 2000.
 E. Pottier, D.L. Schuler, J.S. Lee and T.L. Ainsworth, "Estimation of the
Terrain Surface Azimuthal/Range Slopes Using Polarimetric Decomposition of
POLSAR Data," Proceedings of IGARSS"99, 2212-2214, July 1999.