Synthetic Aperture Radar imagery modelling and simulation for investigating the composite scattering between the targets and the environment

The high resolution of the Synthetic Aperture Radar (SAR) imagery, in addition to its capability to see through clouds and rain, makes it a crucial remote sensing technique. However, SAR images are very sensitive to the radar parameters, the observation geometry and the scene characteristics. Therefore, SAR simulators capable of generating raw SAR signals under specific acquisition conditions are essential for developing and evaluating SAR systems. The work proposed in this communication aims to develop a methodology to generate raw SAR data and SAR images for a complex scene of interest. More specifically, complex scenes of interest with targets located on a rough surface are considered in the scope of this study. In this context, electromagnetic (EM) phenomena are complex, and a composite scattering field between the targets and the environment occurs and needs to be modelled. This consists of multiple reflections changing the radar signature of the elements of the scene and causing defocus in the SAR image. One of the objectives of the presented work is to use the generated SAR images to extract information about the coupling between the objects and the environment.

With this prospect, the entire radar acquisition chain is considered: the sensor parameters, the atmospheric attenuation, the interactions between the incident EM field and the scene, and the SAR image formation.

Finally, simulations are performed considering different scenarios with a rough dielectric soil and canonical targets considered as Perfect Electric Conductors (PECs) to generate the raw SAR signal and the SAR image with the stripmap and spotlight acquisition modes. Thus, the impact of the different parameters of the radar link on the quality of the reconstructed SAR image is analyzed by distinguishing the parameters of the radar, the observed surface and the objects present on the surface.