When looking to survey waterbodies, our clients are often faced with a choice of opting between a Multibeam or Single Beam survey solution. Part of Total Hydrographic’s role is to help you ascertain what is the most suitable type of survey for your situation. This requires a detailed conversation and in-depth understanding of your survey needs. This two-part blog serves to give you a foundation to understand the two hydrographic survey methodologies, to help you make informed decisions and to hopefully answer any initial questions you may have. This blog post focuses on Multibeam survey and the second part will focus on Single beam survey.

Multibeam Echosounder (MBES)

Total Hydrographic’s Multibeam Echosounder (MBES) is a full bathymetric seafloor coverage system. The MBES system emits 512 beams in a fan shape beneath the boat allowing the system to capture up to 200,000 soundings per second and ensure maximum coverage of the seafloor. Our system meets the International Hydrographic Organisation’s (IHO) feature detection requirements for its most stringent survey standard, IHO Special Order. IHO Special order surveys require feature detection of objects smaller than 1m.

What does this mean for you?                                           

Feature Detection

Multibeam survey has feature detection capability for underwater features >1m to ensure no potential hazards are missed in the area that is under survey.

Figure 1: Feature detection capabilities of MBES allow for hazards to be identified for safe removal
Safety of navigation and under keel clearance

Total Hydrographic’s bathymetric survey data is complemented by accurate motion compensation systems and accurate RTK positioning which ensures that the multibeam survey data is suitable for areas where safety of navigation and clearance are critical to the users of the waterways.

Figure 2: Nautical chart identified compliant and non-compliant areas of channels
Highest Resolution Data

High resolution means you can make more informed decisions regarding what is best for your project without interpolation and ‘guess work’.

Figure 3: A visual comparison between the coverage of single beam echosounder (SBES) and Multibeam echosounder (MBES) surveys
Survey Efficiency

With a swath reach of six times the water depth, MBES is effective at capturing data over large areas.  This efficiency reduces the time that our surveyors will be out on the water capturing data and allows for a faster turnaround time for completion of your project.

Coverage without compromise

A wide sonar swath and beam steering allows for detailed coverage under wharf structures and moored vessels without needing to disturb the public. Data can also be captured on vertical structures such as rock wall groynes and jetty piles.

Figure 4: Vertical structure scanning using MBES to capture data up to the waterline.
Accurate Volume Computations

Greater resolution data improves volume calculation estimates for dredging. A multibeam dredge survey can provide your dredging contractor with all the information they need to know to get the job done efficiently. Target areas can be highlighted and calculated against provided design levels.

Determine Seabed characteristics

High resolution data is required to capture, analyse and categorise the benthic zones of marine environments. Using a Multibeam system, backscatter information can be captured to compliment MBES bathymetry. Sea bottom material and characteristics can be determined from this data.

Figure 5: MBES backscatter showing variation of seafloor across the survey extents.
Fully calibrated and validated system

Our survey system is calibrated and validated on site to ensure you receive the most accurate data possible of your waterbody.

This type of Multibeam survey is suitable for:

  • Shipping Channels, Harbours, Marinas and any waterway where safety of navigation is essential
  • Inspection of underwater features or structures
  • Habitat mapping to identify vegetation/benthic zones
  • Coastal & foreshore developments
  • Larger reservoirs can be surveyed due to efficiency and coverage of system. This can be fully integrated with other datasets such as LIDAR and other terrestrial survey information to gain better understanding of what lies beneath.

Multibeam survey and Single Beam surveys are each best suited to their own individual set of circumstances, locations and client needs. Total Hydrographic can help by recommending a particular solution specific to your own requirements and priorities as both MBES and SBES have their individual strengths and capabilities.

Contact Total Hydrographic today to discuss the requirements of your next project!