Abstract

Spatial resolutions represent a key feature for a good understanding of the imaged target, thus allowing ATC and ATR techniques to be successfully applied. Before going through the spatial resolution definition, we briefly recall the concept of radar image. A radar image can be defined as the spatial distribution of the e.m. reflectivity of an object mapped onto a two-dimensional plane. The target reflectivity is a measure of the electric intensity field backscattered by the target and collected by the radar. The backscattering effect is caused by the e.m. field irradiated by the radar that induces electric surface currents on the illuminated target, which in turn produce an e.m. field that partially propagates back to the radar. Therefore, the imaging radar measures the spatial distribution of the target reflectivity function projected onto a two-dimensional plane. As mentioned before, the finer the spatial resolutions, the more detailed the target radar image which means that different parts of the target corresponding to different reflectivity features can be identified.