High resolution geo-referenced underwater surveys using mobile laser, LiDAR and multi-beam technologies have widespread applications including; contactless metrology, structure mapping, pipeline inspections, mooring chain surveys, inland waterway inspections, scour surveys, seabed coral / fauna mapping, wreck and drilling mud surveys. We are able to support these projects with tightly integrated, acoustically-aided inertial and Doppler underwater navigation, together with all the equipment, planning and operational services that you need to ensure success.
Underwater Mobile Scanning
Until now, because dynamic centimetric-level navigation with fast update rates has not been commercially available, subsea laser and LiDAR systems have predominantly been used in a static mode. Due to the relatively short ranges achievable from these systems (anywhere between five and 30 metres depending on the type of system), multiple scans are required. This involves relocating the system to a number of locations on the seabed to cover the required area, whilst ensuring each scan has common features allowing them to be merged together.
Operationally, this is time consuming, both in terms of physically relocating the scanner, waiting for the visibility to clear after the scanner has been placed on seabed, and then processing time to merge the data together. It also means scans are limited to side views, and not from above.
By adopting a dynamic platform, such as an ROV navigated using Sonardyne’s SPRINT INS, Syrinx DVL and Fusion 6G (sixth generation) LBL acoustics, the site can be mapped much quicker with no issues of reduced visibility as the ROV does not have to come into contact with the seabed at the survey site and can move to scan any target of interest.
For metrology operations, the ability to dynamically position a laser in close proximity to the structures allows operations to be conducted in reduced visibility, reducing delays, and allowing a greater point density over targets.
High resolution point cloud data can contain a wealth of information which can be utilised for various engineering requirements. One survey operation can accomplish multiple tasks and also reveal previously unknown engineering features.