Van Oord, a world leading dredging contractor, is frontrunner in maintenance dredging works with their water injection dredging techniques. Natural influx of mobile muds and induced fluid muds are the environment to be dealt with. The fluid mud itself does not pose any problem for the shipping, but it prevents the surveyor from mapping a reliable nautical bottom. Both high and low frequency channels do not provide stable depth readings.
Van Oord deployed both single and multibeam echosounders. High frequency signals have the tendency of penetrating trough the mud when a very gradual water-mud transition is present. Low frequencies are generally unstable and tuning of the digitalisation settings is required frequently.
To overcome these problems the EBP-10 echosounder/subbottom profiling unit with the Silas data-acquisition package was tested. The high resolution seismic profiles combined with the fast autotracing algorithms appeared accurate and efficient.
Based on the results the system was purchased and is bound for implementation on the site shortly.