Following on presentation of shallow-water multi-beam systems in our December 2006 issue, this product survey focuses on deep-water multi-beam systems. You may have noticed that the previous survey did not fully cover the available systems. Details of GeoSwath Plus, L3 Seabeam 1185, Reson Seabat systems, and Kongsberg 3000 and 3002 are thus included in the present survey. Although most of the systems covered here may be classified as ‘multi-beam’, in fact this designation is not correct; taking into account the sonar methods employed they should actually be classified as ‘swathe bathymetry systems’. Traditional multi-beam systems still make up the majority of those presently used in the field using multi-beam sonar methods. However, phase-measurement systems like the GeoAcoustics GeoSwath Plus and those using a combination of amplitude and phase measurement have proved their advantages over the traditional multi-beam system.

Users nowadays understand ‘deep water’ to refer to depths exceeding 1,000m. Multi-beam systems designed for ranges greater than 300-500m we here consider ‘deepwater’ systems. They operate at lower frequency, ranging from five to 80kHz. A further growth in demand for deepwater marine survey has been noted, especially in the oil & gas industry and oceanographic research. The need for higher resolution and more reliable data has led most manufacturers to improve specifications and introduce new versions of their systems.

Since our last product survey on deepwater multibeam systems in 2003 we have also noticed a growth in demand for multi-beam/swathe bathymetry systems for AUV/UUV applications. Where further range extension becomes technically difficult to achieve, systems are being integrated into ROV/AUV/UUV vehicles, allowing the systems to descend to required depths and so attaining ‘deepwater’ capabilities.

Participating suppliers:

• Atlas Hydrographic
• GeoAcoustics
• Kongsberg Maritime
• L-3 Communications ELAC Nautik GmbH
• Reson