Imaging from random targets by in-door SAR experiments

Radar remote sensing of earth surfaces is by transmitting and receiving scattering signals from random surface and volume scatters, from which the target information content can be derived. Recently, more and more attentions are focused on random scatter properties in view of SAR imaging, for example, sea surface, ice or vegetative covers, bare soil, et al‥ Besides theoretical and numerical studies, the experimental observation offers information and instructions for investigations on the imaging and retrival algorithm development. In this paper, we present our recent progress in experimental studies upon scattering imaging from the artificial target, such as a rough surface model or a plant-like object. A Ka-band with 2 cm high spatial resolution ground based SAR imaging system, based on a vector network analyzer and a scanning track in a full wave chamber, was set up to carry out experiments. A target zone of 30 cm plus 30 cm is guaranteed to support the random target within the view of SAR imaging, which allows us to investigate the scattering mechanism and image formation. The design of experimental imaging observation for the random target is presented and discussed, in aspects of target design, measurement parameters and data processing. We also discuss the scattering from the edges or supports of the random targets that contributed to the total receiving signals, a disturbing effect in the general experimental studies of scattering from artificial random targets. The scattering mechanisms of the random target were analyzed from image and scattering pattern results, as well as their physical connections.