Design and Performance Evaluation of Non uniform Pri Radar Signals

Abstract

newline Abstract newlineRadar systems transmit electromagnetic energy into the free newlinespace and use the reflected energy to detect, locate and estimate the newlinerange and velocity of the target. Range and velocity of the target are newlineassociated with the delay and Doppler shift of the signal received newlinerespectively. The detectability of the target depends on the receive newlinesignal energy, the range and Doppler resolution of the target depend newlineon the transmitted signal envelope. newlinePulse compression is a signal processing technique used to newlinemaximize the sensitivity and range resolution of pulsed radar systems. newlineIn pulse compression technique a long coded pulse is transmitted and newlinethe received echo is processed to obtain relatively narrow pulse. The newlineambiguity function, which describes the complex envelope of the newlinesignal at the output of the matched filter as a function of radar target newlinerange and Doppler, is used to study the resolution characteristics of newlinethe waveforms. newlineConventional radar systems transmit a single pulse and use the newlinereceived signal to detect and estimate the distance of the target. Pulse newlineDoppler radars further estimate the velocity of the target by newlineperiodically transmitting pulses. The progressive phase shift of the newlinereceived pulse is used to measure the velocity of the target. newlineConventional uniform PRI systems suffer from limitations like blind newlinespeeds, jamming etc. These limitations can be overcome by using nonuniform newline newlinePRI waveforms. Further the range resolution of these newlinewaveforms can be improved by appropriately choosing the PRIs and newlinebasic pulse shapes (PCW, LFM, Stepped LFM and Costas). This thesis newlineinvestigates the design of non-uniform PRIs with different basic pulse newlineshapes to simultaneously improve the Doppler and range resolution of newlineactive sensor systems like radar and sonar. newlineV newline newline The delay and Doppler resolution of the waveforms are studied newlineby evaluating the peak sidelobe ratio (PSLR) and integrated sidelobe newlineratio (ISLR) of these waveforms from their respective ambiguity newlinefunctions. Low PSLR is desired to avoid f