M3 Sonar: Multiple Modes for Multiple Applications

By: Sarah Pilkington, Kongsberg Mesotech Ltd.

Underwater surveys, obstacle detection, and harbor security inspections are only a few of the applications challenged by high currents, lack of visibility, and other subsea hazards. For over 40 years, Kongsberg Mesotech acoustic systems have been successfully used worldwide to augment diver inspections and underwater visualization operations. The use of multibeam technology enables faster operations than traditional scanning sonar and provides a large coverage area for data acquisition and a real-time data display. Kongsberg Mesotech’s M3 Sonar can be used for both imaging and profiling applications. The M3 Sonar delivers high-resolution and easy-to-interpret images by combining the rapid refresh rate of conventional multibeam sonar with image quality comparable to scanning sonar and is suitable for a variety of deployment platforms, including remotely operated vehicles (ROVs), pole mounted on a vessel, or mounted on a tripod. Exclusive to the M3 Sonar is the multimode capability that, in addition to standard imaging and profiling, features a unique enhanced image quality (eIQ) mode designed to provide image quality comparable to high-resolution scanning sonars. With four pre-defined operating modes, the M3 Sonar delivers application capability not found in any other system. Operating Modes 1. Imaging: long-range navigation with a fast update rate 2. Enhanced Image Quality (eIQ): greatest image quality from a short range with a slightly slower update rate 3. ROV Navigation: automatically selects eIQ or imaging based on range 4. Profiling: optimized split beam profiling for bathymetric surveys.

“We are thrilled at the feedback received from customers after seeing the M3 Sonar’s imaging and split beam profiling data”, said Colin Smith, Multibeam Product Manager. “Having the multimode capability in one unit gives the M3 Sonar a distinct advantage over other multibeams.”

M3 Sonar pipeline survey (profiling data and image mosaic).

M3 Sonar Head

M3 Sonar software features:
• Real-time 3D point cloud
• Automated GeoTIFF export for image mosaics
• Dual head synchronization abilities

M3 Sonar can be integrated with third-party software for real-time profile data acquisition and post-processing. Faster Operations M3 Sonar operations are faster than manual diver searches and conventional scanning sonar surveys, resulting in reduced risk and lower costs. An initial search can be completed prior to dive team mobilization, with targets and potential hazards identified before the first diver enters the water. Dive time and associated risks are substantially reduced using the M3 Sonar.

Image of 26’ sunken sailboat.

M3 Sonar Applications
• ROV Navigation and obstacle avoidance
• Marine engineering
• Site inspection and visualization
• Environmental monitoring
• Pipeline survey
• Berth clearance

M3 Sonar mosaic image of a shoreline.

Flexible Applications The multimode capability of the M3 Sonar allows the operator to quickly switch from one operating mode to another. After locating a target using forward imaging, the operator can switch to profiling for 3D point cloud generation. The M3 Sonar System is Kongsberg Mesotech’s latest development in acoustic systems, and the company continues to make technological advances and is expanding its product lines through extensive research and development. To view M3 Sonar data videos and learn more, please visit www.km.kongsberg.com/M3Galleries.