The Glossary, therefore, should not be used as general reference for hydrographic, navigational or information technology terms.Some of the relevant IHO specifications contain a glossary of terms on their own.chart symbol A character, letter, line style, or similar graphic representation used on a chart to indicate some object, characteristic, etc. colour system Colour specification system established by the Commission Internationale de l’Eclairage, which permits a replicable description of any colour on any equipment; in contrast with other colour schemes, which are apparatus specific. clarifications section One of the mechanisms used to maintain S-57. clutter Excess information or noise data on a display reducing its readability.
Cross references to other definitions in the Glossary are provided by italicizing the respective term.
Acronyms are integrated in the Glossary with cross references.
[TS] Note: An example of a collection object in S-57 is “aggregation” which is used, for example, to group together the different objects which together constitute a Traffic Separation Scheme.
colour calibration In order to reproduce the IHO colours for ECDIS, a colour calibration at the monitor must be performed to transform the CIE-specified colours for ECDIS into the colour coordinate systemof the screen.
It has been completely revised based on the latest editions of the relevant ECDIS-related standards and specifications.
The reader should be aware that it is not intended to cover everything that has a bearing on ECDIS, and that many definitions only reflect a rather narrowmeaning the terms have in conjunction with ECDIS.
Preface The purpose of this Glossary of ECDIS-related terms is to facilitate reading and interpreting the standards and specifications related to ECDIS issued by IMO and IHO, namely the ECDIS Performance Standards, the IHO Special Publications S-52 (including its Appendices) and S-57.
This 3rd edition has been developed by the Glossary Working Group of the IHO Committee on Hydrographic Requirements for Information Systems (CHRIS).
[Bowditch] AIS See Automatic Identification System. alarm An alarm or alarm system which announces by audible means, or audible and visual means, a condition requiring attention. the mariner keying in update information, or the software inside ECDIS automatically processing the ENC update information. In the data structure, the attribute is identified by its label/code. attribute label/code A fixed length numeric label or a 2-byte unsigned integer code of an attribute as defined in Appendix A, IHO Object Catalogue. Automatic Identification System (AIS) An automatic communication and identification system intended to improve the safety of navigation by assisting in the efficient operation of vessel traffic services (VTS), ship reporting, ship-to-ship and ship-to-shore operations. [UG] Automatic Radar Plotting Aid (ARPA) A system wherein radar targets are automatically acquired and tracked and collision situations computer assessed and warnings given.
[PS] all other information Term used in the Performance Standards for ECDIS to describe information not belonging to the standard display. [UG] area The 2-dimensional geometric primitive of an object that specifies location. The acronym is only used as a quick reference in related documents and in ENC Product Specification. azimuth The bearing of a geographical position, measured clockwise from north through 360 degrees.
[HD] cell The basic unit for the distribution of ENC data covering a defined geographical area bounded by two meridians and two parallels, the content of which must not exceed 5 Mbytes, and which is intended for a particular navigational purpose. chain node Data structure in which the geometry is described in terms of edges, isolated nodes and connected nodes.