Practical Applications of an Integrated Acoustic Positioning System

摘要

A rapidly growing, world wide demand for dynamically positioned vessels to operate in water depths to beyond 2500 metres requires reliable and redundant position reference systems. For operations on the continental shelf, adequate acoustic positioning information has been available from Short Baseline and Ultra Short Baseline equipment. The move towards deeper water is placing demands on improved repeatability and accuracy of acoustic position reference equipment, which is better met by Long Baseline equipment. Sonardyne have recently introduced integrated Long/Short Baseline and Long/Ultra Short Baseline systems which combine the accuracy of Long Baseline with the convenience of the other methods. The system design has circumvented the delays which can arise when deploying and calibrating Long Baseline arrays as these operations can be carried out concurrently with providing positioning information to the DP system. Changing between the different modes is a seamless operation requiring no operator intervention. This paper outlines the integrated system design and describes the data processing techniques and operational procedures which have been adopted, with practical illustrations taken from operations carried out over the past twelve months in water depths down to 1800 metres.