Superresolution of Chirp Signals and Its Applications to Three Dimensional Imaging of Maneuvering Targets
For a maneuvering target, the Doppler of scatterers take the form of LFM signals after movement compensation. Superresolution methods are based on the models of both the signal and the noise. In this paper, we extend the Relax algorithm to the case of LFM signals and apply it to monopulse three dimensional imaging. Simulation results shows that the images thus formed are superior to those formed by the traditional dechirping method.
We present a computer simulation study of thin crystalline multilayers constructed from two FCC solids with differing lattice constants and binding energies. Both materials are described by Lennard-Jones interatomic potentials and initially have the same orientation and coherent interfaces. We have studied systems in which interfaces are perpendicular to the common [100] and [111] directions, respectively. A novel technique for analyzing local atomic ordering, Common Neighbor Analysis, is used to identify structural characteristics in these systems. We have found several structural changes in the layers of smaller atoms, including an FCC to HCP transition. In a system with (111) texture, a coherent interface to incoherent interface transformation is observed. Calculations of elastic constants of these multilayer structures show that elastic anomalies are associated with the structural variations.