Filters

Vessels in the AIS Server are selected through filters, which define groups of vessels. Filters are used when viewing vessels both in lists, on maps, and when exporting data.

Filters are added, edited and deleted using a web-based interface, and are saved on the server. The filter is given an identifying name that is used both when viewing and exporting data.

A filter is composed of one or more filter constraint, and if a vessel satisfies all constraints in a filter, it will be selected. A constraint is defined by an attribute, an operator (either "=", "!=", "<" or ">") and a value. Attributes are usually AIS attributes (such as vessel name, IMO number, position, etc.) but could also be certain calculated values.

AIS attributes

At the moment, the following AIS attributes are available:

  • Ship name
  • Country
  • Ship type
  • Cargo
  • Ship operation
  • Rate of turn
  • Speed over ground
  • Course over ground
  • Heading Destination
  • Length
  • Longitude
  • Latitude
  • Navigational status
  • Position accuracy
  • RAIM flag
  • MMSI number (list)
  • IMO number (list)
  • Call sign (list)
  • Destination (list)
  • Source type
  • Source name

Calculated attributes

Some calculated attributes are also available:

  • Active
  • Inactive time
  • Max speed over ground
  • Missing dynamic data
  • Missing static data
  • Inconsistent data

In addition it the user can specify a map region to be used as default map region and a geographic position to be used for calculating distance from a vessel.