The creation of ENC based on source data requires much more effort than the creation based on paper charts. Survey data from
are used. The source data will be pre-processed using filter algorithms. So that the data quantity becomes manageable.
Furthermore data from administrative and legislative bodies, commercial users and infrastructure information can be added, e.g.
The vector data must be correlated with S57 objects and attributes have to be assigned.
Corrections which have been published during the process have to be implemented.
Finally, the ENC has to be checked and validated. Only ENCs which have passed both check and validation can be used for navigation.
Following example provides an overview of the efforts to be made if evaluating source data.
In the past single depths were sounded and the depth contour of a sea chart was modeled from those depths. Nowadays, with the use of multi beam sonar or SideScan sonar, the data quantities can not be compared.
A standard conform survey can produce between ~27.000 and ~670.000 measurements per nm2. Surveying an area with multi beam sonar 250 single depth have to be checked per measurement, with SideScan sonar the quantity is much higher.