The present invention is an improved system and method for detecting the leading edge of a waveform. More specifically, the invention relates to detecting the leading edge of an ultra wideband waveform. The invention requires locking to the ultra wideband waveform at a lock reference time, and sampling the ultra wideband waveform during one or more time windows relative to the lock reference time to identify one or more leading edge candidate times based on one or more detection criterion. The ultra wideband signal is sampled at a band limited Nyquist rate that avoids aliasing within a band of interest of the ultra wideband waveform, but allows aliasing outside of the band of interest to minimize the number of samples for leading edge detection processing.