Studies into the detection of buried objects (particularly optical fibres) in saturated sediment. Part 1: background

Abstract

Damaged submarine fibre optic telecommunication cables have, in the past, beenlocated by the use of remotely operated underwater vehicles. These are fitted withsensors which have the capability to detect the metal shielding in the metallic coresused in cable technology. However, it is anticipated that the next generation of cableswill have a much reduced metal content, their strength being derived from syntheticmaterials such as aramid fibres. Such structures will have greatly reduced contrast fordetection by both electromagnetic and acoustic radiations transmitted from anunderwater vehicle, to then propagate through the seabed and scatter off the cable.The detection of such cables will require new approaches.This report is the first in a series of five written in support of the article “Thedetection by sonar of difficult targets (including centimetre-scale plastic objects andoptical fibres) buried in saturated sediment” by T G Leighton and R C P Evans,written for a Special Issue of Applied Acoustics which contains articles on the topic ofthe detection of objects buried in marine sediment. Further support material can befound at http://www.isvr.soton.ac.uk/FDAG/uaua/target_in_sand.HTM