Hydrographic data is position-determined information about actual objects and phenomena in the coastal zone, such as wrecks, fairways, depth and coastline and other information necessary for safe navigation. The data is used in the production of electronic charts and customized products such as printed paper charts and small craft charts.
The Chart Database is part of the hydrographical data administered by the Swedish Maritime Administration. The two most important products generated from the Chart Database are printed charts and electronic charts for use in navigation systems. Data is also provided to other GIS users.
Swedish navigational charts are stored in the Chart Database. The information is divided into various scale ranges: port, special, archipelago and coastal charts, where the scale range containing port information is the least generalised and contains the most detailed data. The scale range with coastal information contains extremely generalised information.
The database is continually updated and updates are distributed to users of digital charts and published in Notices to Mariners, NtM, which are issued once a week.
The main source of data in the database is analogue charts that have been digitalised, meaning that the information in the database maintains the same standards of quality as analogue printed. A higher ambition is to create “safe sea routes,” which would entail improving the information about the most important Swedish fairways by means of an entirely electronic production line, from measurement input to chart. This also makes it possible to present depth contours other than those currently included on navigational charts.
Standard for digital chart information
The Swedish Maritime Administration’s Chart Database is based on the IHO (International Hydrographic Organization) standard for digital chart information. The S57 standard was officially adopted by world navigational chart institutions in 1992 and is applied when digital chart information is transmitted.