Hydrographic Surveys

Spatialmaps focuses on delivering hydrographic and bathymetric surveys services through latest technologies with wide partnership across players in the industry.

Our Survey team would typically provide horizontal and vertical survey control points along the corridor to be surveyed.  We would then provide topographic surveys of the ground surface down to the water level.  Survey control information would  provide controls framework  for  conducting the Hydrographic or Bathymetric Surveys allowing design of infrastructure along the  water front and off-sea infrastructure  constructions.

Our hydrographic capacity includes operate vessels equipped with the latest multibeam, sector scan and single beam echo sounders, on-board processing and data displays, real-time centimetre level GPS position fixing, current metering ,side-scan sonar and magnetometers.

Bathymetric surveys allow surveyors and hydrographers measure the depth of a water body and map the underwater features of a water body.  Multiple methods can be used for bathymetric surveys including multi-beam and single-beam surveys, sub-bottom profilers, and the Ecomapper Autonomous Underwater Vehicles.

 

Bathymetric surveys are used in various fields including port habour dredging and monitoring, contour of streams and reservoirs, leakage, water-quality studies, dam removal, biological spill,storage and fill in reservoirs and ponds.
In single beam bathymetry, an echo sounder is used to measure the depth by sending out a acoustic signal.

Even though there has been advancement with multibeam, single beam still remains a valid methodology for surveying especially on shallow  water environments where the time required to achieve 100% insonification with a multibeam sonar is excessive or beyond a client’s budget.

Multi-beam surveys are used to gather detailed information about the features on the seabed by measuring multiple depths from a single transducer array at high resolution.Multibeam surveys are routinely carried out in support of dredging projects for ports, harbours,offshore projects  and facilitate the accurate calculation of dredge volumes.

Applications.

    • • Bathymetric surveys of ports, harbours and the open waters
    • • Dredge volume calculations
    • • Nautical chart production
    • • Ground discrimination and seabed mapping
    • • Underwater search and hazard identification
    • • High resolution wall and structure inspection
    • • Reservoir volume calculations.

Sub-bottom profiling systems identify and measure various marine sediment layers that exist below the sediment/water interface. These acoustic systems use a technique that is similar to single beam echo sounders.

A sound source emits an acoustic signal vertically downwards into the water and a receiver monitors the return signal that has been reflected off the seafloor. Some of the acoustic signal will penetrate the seabed and be reflected when it encounters a boundary between two layers that have different acoustic impedance. The system uses this reflected energy to provide information on sediment layers beneath the sediment-water interface.

 

Practical Applications.

  • Measure  and detect the thickness of dredged material deposits,
  • Detection of  hard substrate that has been covered by sedimentation, identify buried objects (such as cables and pipelines),
  • Measure and define the basement (or bedrock) layer for potential confined aquatic disposal sites for dredged material. Data can be displayed in various 2D and 3D formats such as is accomplished by SonarWiz+SBP.

These Surveys support detecting and imaging objects on the seafloor. The multiple physical sensors of the sonar — called a transducer array — send and receive the acoustic pulses that help map the seafloor or detect other objects.

Side-scan sonar is commonly used to locate potential seafloor hazards such as former bridge piles and wrecks, mapping seafloor utilities, evaluating reefs, mapping sea grass and performing grain size surveys. The high resolution images are capable of imaging objects as small as several inches in size.

Hydrographic and Bathmetric surveys are routinely undertaken on ports,rivers, reservoirs to  survey for safe passage and navigation, reservoirs desilting, water way routing channeling amongs many uses.


We have software technology that supports 3D dredge modeling allowing us  provide detailed and accurate volume calculations, quantify the amount of material removed and show areas of accretion or erosion.