| This dissertation develops one and two-dimensional signal processing models and algorithms which are utilized in the Radar Target Identification Problem. A basic assumption of this work is that the high-frequency scattering from a radar target, such as an aircraft, land-based vehicle, or ship, is comprised of the sum of the scattering from a finite number of canonical scattering centers, each with a specific location and identity. By high-frequency it is meant that the overall size of the target is at least one wavelength. The scattering center assumption is more valid as the individual scattering centers become more electrically isolated. If two individual scattering centers are electrically close, then their combined response is, in general, not the sum of their individual responses.; First, this dissertation investigates the electromagnetic scattering characteristics of canonical scattering centers. Canonical scattering centers are scattering centers on a target which account for the vast majority of the scattering from that target in the high-frequency case. Some of the targets of interest in this work are aircraft, tanks, trucks, automobiles and ships. Predominant scattering centers on these targets include corners, edges, plates, dihedrals, trihedrals, and cylinders. The scattering centers are described by their scattering characteristics as functions of angle, frequency, and polarization.; Second, this dissertation develops a two-dimensional (2-D) signal processing technique for locating and characterizing scattering centers from radar data. The radar gathers scattering data of a target at both multiple frequencies and multiple angles. This type of data is gathered (in raw form) by both Synthetic Aperture Radars and Inverse Synthetic Aperture Radars. The 2-D signal processing technique developed here is based on a 2-D extension of a total least squares (TLS) solution to a Prony Model and is called the 2-D TLS-Prony Technique. This technique can use single or multiple-polarization data. With full-polarization data, polarimetric characteristics of the scattering centers are found using the transient polarization response concept. This concept uses an ellipse to characterize the polarimetric characteristics of each scattering center. The abilities of the 2-D TLS-Prony Technique are demonstrated utilizing simulated 2-D radar data. |
