Wideband through wall radar imaging using Green's function aided target density function

This thesis presents a beamforming algorithm operating in the time domain, which employs Green's functions to detect and display targets behind the wall. The developed algorithm refers to a two-stage focusing process that reconstruct a unique target density function determined by the angle and range parameters. A novel Green's function approach is put forward to aid the focusing task. The mathematical derivation is given in the algorithmic form. The nature of through wall imaging systems requires the employment of Ultra-Wideband systems which brings extra advantages and challenges beyond design. A detailed framework is presented about these systems, their standards, features and their role in seeing through the obstacles. An advanced mathematical wall model is analyzed with reference to electromagnetic diffraction and propagation laws. Modern algorithms using the data and geometry of the radar system are presented in order to compute the parameters of the wall, which are desired to be used in the algorithm. Since the imaging geometry with radar requires the target to be illuminated from different points, an antenna array consisting of Ultra-Wideband Vivaldi antennas is designed on the application side. Technical analyzes and simulations of both Vivaldi antennas and the designed antenna array are executed. In both simulation and implementation studies on the designed system, it is observed that the developed algorithm fulfills the focusing task and can successfully map the target density function with angle - range parameters from the raw data received.