3. ANÁLISIS Y DISEÑO
3.4 D ESCRIPCIÓN DE LAS CLASES
IHO publication S-57 • IHO S-57 provides the transfer standard for hydrographic data chart data transfer and to be used with ECDIS.
updating • It describes the data structure and format to be used for the exchange of ENC (Electronic Navigational Chart) data between hydrographic offices, ECDIS manufacturers, mariners and other users.
IHO special publication • Specifications for chart content along with display aspects of
S52 ECDIS.
It provides specifications and guidance regarding the issuing, updating and display of ENC when used with ECDIS.
International • Governs maritime navigation and radio-communication
Electrotechnical equipment systems.
Commission (IEC) • Describes the Electronic Chart Display and Information standard 61174 System (ECDIS), operational and performance requirements,
and provides methods for the required results.
IMO Resolution A.817(19) • IMO Performance Standards for ECDIS.
• Describes the minimum performance standards for ECDIS systems, references to both hardware and software, ENC updates, user interface and the integration of external devices.
• IHO and the IEC based the development of their publications (IHO S-57, 52 and IEC 61174) on IMO resolution A.817(19).
Definitions
Integrated Bridge System An Integrated Bridge System (IBS) is a combination of systems, (IBS) which are interfaced to allow centralised access to sensor information
or command/control from individual workstations.
Electronic Chart Display A navigation information system which, with adequate backup and Information System arrangements, can be accepted as complying with the up-to-date (ECDIS) chart, required by regulation V/19_2.1.4 of the 1974 SOLAS Convention, by displaying selected information from a System Electronic Navigational Chart (SENC) with positional information (referenced to WGS-84) from navigation sensors to assist the mariner in route planning and route monitoring, and by display additional navigation-related information.
ECDIS certified systems To qualify as an ECDIS system the hardware and software must be simultaneously tested by an authorised Classification Society in accordance with the IEC 61174 requirements, and be granted an approval certificate
The approval is only valid in the sea areas for which the official S57 chart data (ENC) has been installed in the system, and corrected to include the latest updates. In all other situations, updated paper charts must be carried on board to comply with SOLAS Regulation V/19_2.1.4.
Electronic Navigational The database, standardised as to content, structure and format, Chart (ENC) - S-57 vector issued for use with ECDIS on the authority of government
authorised
chart hydrographic offices. The ENC contains all the chart information necessary for safe navigation and may contain supplementary information in addition to that contained in the paper chart (e.g.
sailing directions) which may be considered necessary for safe navigation. Hydrographic offices can directly produce this data or they may commission private companies to produce the data and then verify and certify the results.
System Electronic A database resulting from the transformation of the ENC by Navigational Chart ECDIS for appropriate use, updates to the ENC by appropriate
(SENC) means, and other data added by the mariner. It is this database that is actually accessed by ECDIS for the display generation and other navigational functions, and is the equivalent of an up-to-date paper chart. The SENC may also contain information from other sources.
Standard display The level of SENC information that shall be shown when a chart is first displayed on ECDIS.
Base display The level of SENC information which cannot be removed from the ECDIS display, consisting of information that is required at all times in all geographic areas and all circumstances. It is not intended to be sufficient for safe navigation.
Electronic Chart Systems An Electronic Chart System (ECS) can be considered any other (ECS) —not ECDIS type of electronic charts that does not comply with the IMO
Performance Standard for ECDIS. Electronic Charting Systems do not necessarily comply with the up-to-date chart requirement of V/
19_2.1.4 of SOLAS 1974. As such, an ECS is an aid-to-navigation that should always be used with an up-to-date paper chart from a government-authorised hydrographic office.
Vector type charts In a vector-based system, electronic chart data is comprised of a series of lines (vectors) in which different layers of information may be stored or displayed.
This form of so-called intelligent spatial data is obtained by digitising information from existing paper charts or by storing a list of instructions that define various position referenced features or objects (e.g. floating buoys).
With a vector ECS, the user has considerable flexibility and discretion regarding the amount of information that is displayed for the task at hand.
Raster type charts A raster chart is a scanned image of a paper chart. In raster-based systems, the data is stored as picture elements (pixels). Each pixel is a component of the chart image with a defined colour and brightness level. Raster-scanned images are derived by video or digital scanning techniques, which result in a computer photograph of paper charts.
Further reading
The intention of this chapter was to provide an insight into the use of complex electronic navigation systems on board ship. It is necessarily brief and only touches the surface of many complex issues. For those readers with a desire for greater knowledge, more information can be found on the internet from a variety of sources: all system manufacturers and government authorised hydrographic offices have their own web-sites with varying amounts of technical information.
Other information can be found using appropriate search engines.
For more information on the electronic chart, its construction and potential, the following publication is highly recommended:
Hecht/Berking/Buttgenbach/Jonas/Alexander, "The Electronic Chart - functions, potential and limitations of a new marine navigation system," published by GITC bv, Lemmer, The Netherlands, ISBN: 90-806205-1-3.
Notes >
1 IMO Model Course 1.27, 'The Operational Use of Electronic Chart Display and Information Systems (ECDIS)', Introduction, p.l: IMO Requirements, §(B) Competence Requirements.
2 IMO Model Course 1.27, p.2.
3 ibid., p.6
4 'The International Code for the Safe Operation of Ships and for Pollution Prevention', now Ch. IX of SOLAS 2001.
5 ISM Code, §6.3.
6 ibid., §6.4.
7 ibid., §6.5.
8 Own suggestion.
9 ISM Code, §8.3.
10 IMO Model Course, p4.
11 Australian Maritime Safety Agency ECDIS Policy (Consult), Nov. 2001.
12 AMSA Marine Notice 14/2002.
13 1974 SOLAS Convention, as amended, Chapter V, Reg. 19.2. (bold text inserted for emphasis).
14 IMO Circular SN/Circ.217.
15 UK MCA has published guidelines on the use of risk assessment methodology to determine the level of paper charts to be carried in conjunction with ECS/ECDIS — MGN 194(M). This can be downloaded from their website: www.mcga.gov.uk Note that it is 32 pages.
16 1974 SOLAS Convention, as amended, Chapter V, Reg. 2. (bold text inserted for emphasis).
17 (Definition: IEC 1290 Integrated Bridge Systems).