'Middle East Technical University, Faculty of Architecture'
Abstract
In this thesis, a method of optimization of nonuniform pulse repetition interval for pulse Doppler radars is investigated. PRI jittering technique is used for the selection of inter-pulse intervals. An environment with white Gaussian noise and clutter interference is defined and applying generalized likelihood ratio test, a sufficient statistic function for the detection of the target is derived. The effect of jitter set selection on range and Doppler ambiguity resolution and clutter rejection is investigated. Jitter sets for Doppler ambiguity resolution are investigated by the minimization of the sufficient statistic function value at other estimated target velocities. Jitter sets for range ambiguity resolution are investigated by minimization of the number of ambigous hits at other estimated ranges. The clutter rejection properties of jitter sets are evaluated by defining a constraint function on zero velocity clutter rejection. The problems stated are solved using MATLAB with genetic algorithms. It is observed that there is a trade off between Doppler ambiguity resolution and clutter rejection properties of jitter sets. Low jitter values are needed for good clutter rejection. The performance of jitter sets are optimized according to range ambiguity resolution and clutter rejection properties by defining cost functions. It is observed that good range ambiguity resolution and clutter rejection can be achieved by an optimized PRI jittering technique. Finally, the effects of quantization of Doppler filter coefficients and target returns using improvement factor as the performance criterion are evaluated.M.S. - Master of Scienc
