Development of a Digital Acoustic Profiler for Ice Rubble

摘要

This paper describes the development, operation and performance of a digital acoustic profiler for ice rubble. Designed for an indoor ice basin, the device is an upward looking underwater profiler which uses a swept frequency or "chirp" waveform to provide high resolution measurements of the underside of ice rubble. Six send/receive transducer pairs are mounted on an underwater carriage in the tank. During data collection, the carriage rolls along the bottom of the tank allowing the transducers to acquire data. The data are post-processed to produce profiles at six locations across the width of the tank. This device is a low cost, self-contained unit which can produce ridge or rubble profiles within minutes of data acquisition. Comparisons with manual measurements of ice rubble depth indicate that profiles can be measured more expediently, with comparable accuracy and at better horizontal resolution using the digital acoustic system.