Aspect Surveys

Aspect Land & Hydrographic Surveys own and operate a Kongsberg EM3002 shallow water high definition multibeam (MBES) system. This system is optimized to operate in depths between 0.5 and 200m. The system operates a swath width of 4 x water depth as standard. When operating in extreme shallow water and when the client requires 100% seabed insonification we prefer to utilize a second transducer making this system a dual head EM3002, capable of swath widths up to 10x water depth and thereby reducing the time taken on the data gathering task very significantly. The system was purchased in September 2006 and has been used extensively on a wide variety of projects including: - Bathymetric surveys to IHO Special Order standard - Environmental surveys - Offshore renewable energy projects - Dock wall inspections - Marine archaeology projects - Wreck and object detection - Dredging control and monitoring 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.