Aspect Land & Hydrographic Surveys

Based upon comparative data sets, it is widely accepted that multibeam sonar, particularly when used in conjunction with RTK GPS equipment, represents a substantial improvement over alternative survey methods in determining seabed characteristics.

Specific benefits of multibeam technology include the ability to map contours without regard to the relative orientation of the track line; sufficient resolution to allow detailed macro scale modeling, classify seabed geomorphology, detect features, objects and gouges with incision depths as small as 0.1 m.

Utilising sub-metre Global Positioning and RTK when possible as well as premium motion and heading sensors lends a hitherto unprecedented degree of repeatability to the bathymetry and also to the seabed geomorphology enabling interpretation from the MBES backscatter.

We currently integrate Trimble Geodetic Grade GPS receivers for Real Time Kinematic GPS positioning providing horizontal and vertical precision better than ±0.03m. When outside the range of RTK the Trimble 461 sub-metre precision GPS receiver is utilised. Heading comes from a permanently installed Trimble MS860 dual antenna GPS which is also able to provide an accurate speed output to the multibeam system. An MRU5 motion sensor is mounted on the transducer bracket of the Multibeam to provide accurate vessel orientation and minimise offset lever arm errors.

This integrated sensor suite guarantees that IHO Special Order standards can be met and also that data gathered from our vessels is of the highest quality, making the most of the available technology.

Our personnel are experienced in the gathering of high quality bathymetry, which ensures that the data taken forward into the processing phase of the MBES survey is of the highest quality. Our custom-built road transportable survey vessels have been designed specifically with multibeam bathymetry in mind and this combination of personnel, vessel and equipment has proven to provide a professional and cost effective approach, achieving data quality to the highest standards.

With limited mobilisation time and virtual 'plug and play' setup, we offer an excellent hydrographic survey service to our clients whether using our own vessels or a contracted platform.

Click on any of the images below to view our multibeam survey capabilities in more detail.

Offshore Wind Farm	Rock Outcropping	Pier Structure	Sand Waves	Sheet Piling

Shipwreck & Scour	Dock Wall Survey	Coastline Survey	Large Scale Mapping	Outfall Diffuser

MBES systems are particularly susceptible to errors associated with sound velocity variation either temporally or geographically. As a result we operate a Valeport mini SV probe to conduct sound velocity profiling over the full water column of the area being surveyed in addition to an OSIL SV&P probe mounted immediately adjacent to the transducer in order to highlight any changes across the operating area or time on task. Data capture and post processing is achieved using the Kongsberg Maritime SIS and HYPACK® Inc. Hysweep and Fledermaus software. Additional software is utilised as the individual project demands.

The system has excellent backscatter seabed image reflectivity and we use this data to interpret the seabed geomorphology digitally through processing in HYPACK® HYSWEEP® or other processing packages as particular projects demand. Additionally this system is capable of mapping water column biomass and artifacts which is particularly useful in identifying biomass, oceanographic features and wreck investigation due to the great detail able to be gathered.

We have operated the equipment in shallow water depths and have also achieved excellent data quality in saltwater depths of 170m.

Although the Kongsberg Maritime EM3002 is the primary system that we use we will utilize other systems as required to fit individual surveys or projects. Data gathering and processing using HYPACK® HYSWEEP® means that we can integrate these different sensor suites while maintaining the highest operator capability levels.