POLINSAR for FOPEN using flashlight mode images along circular trajectories

The airborne radar system RAMSES collected data over the Sweden forest to investigate the capabilities of detection at P-band and influences of different SAR parameters like resolution, central frequencies, and look angle. During this campaign, circular trajectories have been performed in order to analyze the presence of anisotropic scattering from the targets at P-band. We show the treatment of two circular trajectories using the Flashlight imaging mode and its ability to collect several SAR data with different look angles. The scope of this paper includes a general description of the operating mode of flashlight SAR images in the interferometric mode and the use of it for FOPEN purpose. The capabilities of detection of such polarimetric images have already been investigated, but without using the interferometric mode [1]. It had been shown that using circular trajectories at P-band was necessary to detect targets: first in our configuration detection was very difficult because the forest was very dense, secondly the targets were very sensitive to the orientation angle of the radar, which should not be the case at lower frequencies. Moreover, polarimetry and polarimetric interferometry are useful tools once the acquisition conditions ensure that detection is possible. Now, the full polarimetric and interferometric information are used in order to explore the potential of the POLINSAR circular mode to yield high detection rate.