Conventional sidescan sonar and multi-beam (Tritech, Kongsberg, Reson, etc) can give positional information but on surface features only. It can only image exposed cables and other seabed features and not buried geohazards. The sub-bottom profiler (Edgetech, Kongsberg, Ixsea, Innomar, etc) can see sub-seabed but only a single 2D line with limited resolution and would require multiple lines and crosslines to cover the proposed route.
Magnetometer (Innovatum, TSS, “Pipetracker”, etc) works on the basis that field measurement infers position but requires target details. Magnetometer will identify magnetic anomalies along the route corridor but sizing of objects is difficult to determine, also non magnetic geohazards would not be identified. Pipetrackers are not used for pre-route survey.
Our Sub Bottom Imager gives a full 3D image of sub-seabed down to around 6m depth and 5-8m swathe and can see both man-made and natural non-metallic targets. It can also identify the accurate depth of live cables – the only technology that can currently do this. The SBI can be used for the initial pre-lay survey on a chosen cable route, identify anomalies which could cause lay problems, identify possible alternative and carry out a post-lay survery to verify accuracy.