Time-delay estimation using a chirp-like signal

To increase the accuracy and the rate of coverage of a given area in shallow coastal waters, light detection and ranging (lidar) airborne laser systems have been introduced. A new technique for time-delay estimation from signals corrupted with noise or clutter is introduced. It is well known that for a given level of noise, a matched filter produces the largest possible peak output in response to each echo signal. In this way it maximizes the probability of detecting valid signals with a threshold detector. It is shown that a chirp-like signal in conjunction with an appropriate matched filter can improve the resolution between the surface and bottom reflection of a bathymetric signal.