Waveform design and doppler sensitivity analysis for nonlinear FM chirp pulses

The use of pulse compression to obtain simultaneous long-range detection and good range resolution is described. The types of modulation that can be used to obtain pulse compression are outlined with particular emphasis on their performance under Doppler shift. It is shown that nonlinear frequency-modulated (FM) signals are capable of providing low range-sidelobes while being compressed using a matched filter. A design method for nonlinear FM signals based on window functions is outlined. Simulation results for pulse compression of nonliner FM signals based on four different window functions with Doppler shift are presented. The results are used to define the effects of Doppler shift on the pulse compression. An analysis is presented, and interpreted pictorially, that explains the effects of Doppler shift on the pulse compression. The analysis is also extended to explain the better Doppler performance of hybrid FM pulse compression systems.