Hydrographic Survey FAQs
How does a multibeam echosounder work?
A multi beam echosounder works by emitting short pulses of sound energy and measuring the time it takes for the echo to return. This survey data is then used to create a digital terrain model (DTM) of the underwater landscape and identify hazards, objects and human-made structures.
What are inertial navigation systems?
Inertial navigation systems use accelerometers and gyroscopes to measure acceleration, rotation and other changes in movement relative to a predetermined reference point. This data is then used for precise positioning and orientation of surveying equipment.
What kind of information can be gathered from a hydrographic survey?
Hydrographic surveys provide detailed visualisations of the seabed bathymetry, objects and human-made structures. The data gathered can also be used to assess sedimentation levels, navigability, dredging requirements and infrastructure development.
What are the benefits of using a hydrographic survey?
The main benefit of hydrographic surveying is that it provides detailed information about an underwater area and bed levels which would otherwise not be visible or accessible. Survey data can be used to accurately plan offshore construction projects and inform the installation of cables, pipelines, wind farms and marine infrastructure.
This makes it ideal for planning construction projects in offshore environments as well as assessing potential hazards and evaluating cable routes between two points. It is also useful for maritime archaeology and identifying archaeological sites beneath the water's surface.
What are the risks associated with a hydrographic survey?
Hydrographic surveys involve working in areas with strong currents, changing weather and other potential hazards. As such, it is important that surveyors have adequate safety training and use certified equipment to reduce the risks.
Additionally, surveyors must be aware of the potential environmental impacts associated with their work and take steps to minimise them.
How long does a hydrographic survey take?
The duration of a hydrographic survey depends on the size and complexity of the area being surveyed. Small areas can generally be completed in one to two days, while more extensive surveys may take weeks or even months.
It is important to plan ahead and allow sufficient time for both data collection and post-processing.
How much does a hydrographic survey cost?
The cost of a hydrographic survey varies depending on the size and complexity of the area being surveyed, as well as the equipment used. Generally speaking, smaller surveys tend to be more affordable than larger projects due to the reduced amount of data collected.
What is the maximum water depth that can be surveyed?
The maximum water depth that can be surveyed depends on the capabilities of the equipment being used, and whether the data is acquired from the surface or from a subsea platform. As the water depth increases, the data resolution may decrease, and lowering the sensor closer to the seabed will improve the resolution.
Are hydrographic surveys weather dependent?
Yes, as weather conditions can affect the ability of the survey team to collect data. Strong winds and high waves can not only affect data quality but can also endanger the safety of the team. As such, surveyors must take into account weather patterns and plan accordingly in order to ensure optimal results.