The paper deals with the enhancement of the resolution of polarimetric SAR imagery.
Due to technical constraints on the system design, the azimuth resolution is coarser in polarimetric images than in the mono-channel acquisition of the same SAR sensor. We aim at enhancing the resolution of polarimetric images using a high resolution image. The idea is close to the concept of pansharpening in optic image processing. But unlike optic pansharpening which is used to improve the visual quality of images, we want to preserve the polarimetric behavior of the scatterers in the image so that the resulting image remains useable for classification purpose.
The speckle phenomenon makes the concept of resolution unclear in homogeneous areas. For bright points or point-like scatterers, improving the resolution means decreasing the width of the main lobe of the PSF. This can be achieved by expanding the spectrum of the original image. The location of the SAR spectrum in the Fourier space is directly linked to acquisition parameters: the angular aperture and the bandwidth. Based on the hypothesis of isotropic and white targets we can use the polarimetric behavior of the low resolution image to expand the spectrum while keeping the initial polarimetric behavior.
Post conference note:
My presentation entitled Spectral method for bright scatterers resolution enhancement can be accessed on the POLinSAR 2015 website.