A System Design for Accurate Measurement of the Time of an Acoustic Pulse for a Ship Positioning and Tracking System-Over-the-Peak Detection System.

摘要

An electronic design disclosure of a system which establishes the time of arrival of a rectangular acoustic pulse at a hydrophone is presented. The system attempts to minimize the error in the measurement of the time of arrival, as well as to provide a technique to make this measurement independent of the amplitude of the received pulse. To improve the signal-to-noise ratio, a matched filter approximation is used. To make the arrival time measurement when the signal-to-noise ratio is maximum, an over-the-peak detector is used. Since the measurement uses a characteristic of the signal equivalent to a slope change, the amplitude does not affect the measurement as it currently does on the present threshold system employed on the Mizar. A major consideration in the design was that the proposed system be compatible with the present Mizar system. (Author)