3DSS Sonar: A Comprehensive Sonar Technology

With the growing demand for full coverage and high resolution in shallow water surveying (<50m water depth), there is an opportunity to foster business growth using a compact, comprehensive sonar technology in the same way that compact lidar systems have fostered business growth in terrestrial surveying.

Shallow water challenges

In water depths, less than 50m, bathymetry coverage from traditional Singlebeam echo sounders is coarse and sparse, while coverage from Multibeam sonars is hampered by the water depth itself (e.g., coverage is typically only 3-4 times water depth). Full vertical coverage of walls or pilings and high-resolution 3D imagery is also beyond traditional Multibeam capabilities, despite their importance in shallow water for identifying hazards, locating objects, habitat mapping and mapping of, and around structures.

Furthermore, combining a Multibeam survey with a complementary Sidescan Sonar survey in shallow water also has drawbacks. These include the additional survey time and cost, the high potential for snagging the Sidescan Sonar in shallow water, the challenge in overlaying unregistered datasets, and the lack of a true 3D imaging capability to accurately visualize structures on the seabed and in the water column.

3DSS sonar technology

Ping DSP’s 3DSS sonar is a compact, comprehensive shallow water survey solution available with or without a fully integrated INS and sound velocity sensor and is easily mounted on manned and unmanned vessels, including small USV’s. 3DSS sonar simultaneously provides ultra-wide swath bathymetry, co-registered 3D Sidescan imagery (true 3D Sidescan), and enhanced 2D Sidescan imagery. See advertisement page 9 for data samples.

Ultra-wide swath bathymetry

3DSS bathymetry meets or exceeds IHO Special Order, CHS Exclusive Order, NL Norm A standards and covers a swath width of 8-16 times water depth to a maximum of 200m in depths from 0.7m to 75m with full vertical coverage of structures such as walls and pilings. In 20m of water it is not unusual to achieve a swath width greater than 200m and in very shallow depths (<5m) it is not unusual to achieve a swath width of 16+ times depth. 3DSS bathymetry acquisition and processing are also supported by almost all third-party hydrographic software suites.

True 3D imagery

True 3D Sidescan is unique to 3DSS sonar technology and provides the same image resolution as conventional 2D Sidescan.  However, with 3D Sidescan, each image pixel has a geometrically correct location in three-dimensional space relative to the sonar.  3D Sidescan imagery is inherently co-registered with 3DSS bathymetry and can be best described as a high density, lidar-like, backscatter point cloud.  While there can be as many as 1024 bathymetry soundings across the swath per 3DSS ping, there may be more than 10,000 3D imagery points. In addition to 3D Sidescan, the 3DSS Sonar provides enhanced 2D Sidescan imagery so that direct 2D/3D imagery comparisons can be made.

3DSS sonar provides a compact, comprehensive solution that enables more efficient, and more detailed, surveys in nearshore coastal areas, ports and harbours, riverine environments, and inland waterways over a wide range of applications that include; hydrography, environmental surveys, surveys around complex structures, rapid assessment and change detection surveys, pipe and cable inspection surveys, search and recovery, ice profiling, and water-column surveys.