A new time/frequency technique for detecting chirped signals

A new time/frequency technique is developed to detect chirped signals. Specifically, we detect pulses that become dispersed by transmission through the ionosphere and are manifested as nonlinear chirps. Standard wavelet methods have been shown to be successful in transionospheric signal analysis, but we find they are not the best way to represent the signals of interest. A new wavelet technique is developed, tailored to capture the characteristics of a nonlinear chirp pulse. Experimental results using actual satellite data demonstrate the new method is a useful tool in detection of nonlinear chirp pulses at low signal-to-noise ratios.