Our clients are often faced with a choice between opting for a Multibeam or Single Beam survey solution. Part of Total Hydrographic’s role is to help you ascertain what is the most suitable solution for your situation. This requires a detailed conversation and an in-depth understanding of your needs. This two-part blog serves to give you a foundation to understand the two methodologies. Based on which you can make more informed decisions and to hopefully answer any initial questions you may have. This blog post focuses on Single Beam survey. Read more about multibeam surveys and what they mean in our blog.

Single Beam Echosounder (SBES)

Our Single Beam Echosounder (SBES) survey, captures data using a single beam directly below where the Echosounder system is mounted. Single Beam surveys are at a pre-defined line spacing; for example, 2m, 5m, 20m. The size of these intervals determines the final resolution of the survey.

As Single Beam surveys cannot physically capture 100% of the seafloor, interpolation is required to fill in the gaps in the data. Therefore, it is not guaranteed that the system will detect features that may lay in between the survey lines spacing.  A 5m survey line plan will require significantly less interpolation than a survey conducted with 20m run lines and more likely to capture seafloor features.

Figure 1: SBES survey in a coastal harbour captured with 5m survey lines. Final TIN model and contours were interpolated to create a seamless 3d model.

What does this mean for you? 

Deployable in Almost any Waterbody                                                                   

Single beam systems are robust, smaller in size and weight, allowing them to be mounted on a variety of vessels and positioned with non GNSS equipment such as a Total Station.

Figure 2: SBES positioned by Total Station capturing data in an waterway adjacent to a shopping complex.
Shallow water coverage

Data can be captured in water deeper 0.20m to maximise coverage across the survey extents.

Sediment Analysis                                                                         

Dual frequency analysis (200kHz and 24kHz) can identify sediment layers in water deeper than 1.0m.

Echogram analysis

Inspection of the SBES echogram can identify areas of vegetation or defined features in the water column.

Rapid mobilisation                

With its compact equipment, surveys can often be undertaken by a single surveyor allowing for rapid mobilisation and quick turnaround times for data. Ideal for small dredging and beach renourishment projects.

Figure 3: With the ability to capture data in as little as 0.2m of water, SBES is an optimum solution for data capture in coastal foreshore projects.
Suitable for repeat surveys

Perfect for projects that require frequent or annual monitoring. Data outputs can be compared with previous datasets to analysis sediment transport or generate cross sections to compare change of slope gradients.

Figure 4: Cross sections of a groyne structure surveyed across multiple years and compared against as-designed plan.
Resolution and accuracy up to IHO Order 1b

System can achieve the highest survey order possible for Single Beam Echosounder (IHO Order 1b)

Fully calibrated and validated system

Our survey system is calibrated and validated on site ensuring you receive the most accurate data possible.

Single beam survey is suitable for:

  • Routine surveys of a regularly surveyed area
  • Surveys of small waterways with restricted vessel access.
  • Smaller bodies of water with overhead obstruction requiring Total Station positioning
  • Beach and foreshore mapping
  • Sediment analysis with Dual Frequency echogram analysis
  • Projects requiring rapid mobilisation

The Right Time & The Right Place

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.