Quality analysis of strip map SAR products obtained at EMSL

The European Microwave Signature Laboratory (EMSL) at JRC is a facility designed to carry out different type of measurements including the synthetic aperture radar (SAR) data acquisition within a controlled environment. One of the objectives of this laboratory is to identify the dominant scatterers in a scene as function of measurement parameters such as frequency band, polarization, geometry of the measurement, etc. The system is currently operational in the frequency range 2-26 GHz and allows both monostatic and bistatic geometries, with large frequency bandwidths and azimuth scans. Basically, the image formation can be performed either by moving linearly the target along the cross-range axis (linear SAR), or by rotating the target about a vertical axis (inverse SAR). In this scenario, a number of scenes consisting of arrays of point scatterers have been imaged in order to estimate the focusing capabilities of the SAR processor. The obtained fully polarimetric SAR products show some “artifacts” whose behaviour depends on the polarization, with a strong impact on the cross-polar products. A study about these effects has been addressed in order to set up a procedure for automatically filtering out these “virtual” targets and eventually, in case they were well characterized, to calibrate the cross-polar channels. study of the scattering mechanisms present in the SAR image has been addressed both with the geometrical optics (GO) and the geometrical theory of diffraction (GTD)