ISAR imaging of targets at low elevation angles

The problem of inverse synthetic aperture radar (ISAR) image reconstruction of targets at low elevation angle is considered. In this geometric conditi ons the main causes affecting the reconstructed ISAR image are: the multipa th effect due to the reflection of the Earth surface and the angular motion s of the target produced by external action like wind, fast maneuvering, an d sea waves as in the case of ships. The aim of this work is to analyze the effects that the multipath and the target angular motions jointly produce on the ISAR image, The results show that multipath generates some artefacts in the image whereas the target oscillations undergo a spatial-dependent b lurring of the point spread function of the ISAR system These theoretical r esults are validated by presenting some numerical examples relevant to airc rafts and ships in rectilinear or circular motion, A wide discussion on pos sible solutions of this problem is made in the conclusion.