Transcript ECDIS Electronic Chart Display and Information System

ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Electronic Chart Display and Information System
●
Definition;
●
Legal Aspects;
●
Numeric Cartography:
●
–
Vector Chart;
–
Raster Chart;
Official Charts (ENC, RNC).
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Electronic Chart Display and Information System
ECDIS: An Electronic Chart Display and Information System is a Geographic
Information System (GIS) that complies with International Maritime
Organization (IMO) regulations and can be used in replacement of paper
navigation charts.
GIS: Computer-based technologies for storage, manipulation, and analysis
of geographically referenced information.
A Geographic Information System differs from other computerized
information systems for the following reasons:
1. the information is geographically referenced (geo-coded);
2. higher capabilities for data analysis and scientific modelling, in addition to
the usual data input, storage, retrieval, and output functions.
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ECDIS
Electronic Chart Display and Information System
The system displays information from electronic navigational charts and
integrates position information from the Global Positioning System (GPS)
and other navigational sensors, such as:
1. Radar (Target and display on top);
2. Echo-sounder;
3. Gyro-compass;
4. Wind sensors;
5. Speed-Log;
6. Automatic Identification Systems (AIS).
For these reasons ECDIS represents a real time Geographical Information
System.
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Electronic Chart Display and Information System
Allarms
Software for
Software for
“Route Planning”
“Route Monitoring”
Autopilot
GPS/DGPS
Speed-Log
Gyro-Compass
Navigation
Chart Database
System
(vector)
C.P.U.
Data Logger
Radar
AIS
Real time
Echo-sounder
information
Wind-sensors
Keyboard
Display
Print
Manual
Trackball
Data Input
Mouse
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Electronic Chart Display and Information System
The primary function of an ECDIS is to contribute to safe navigation.
IMPORTANT: ECDIS IS
DECISION PROCESS.
AN
INSTRUMENT
FOR
“SUPPORTING”
There is a tendency to put too much trust in computer based systems and
believe whatever is on the display (Over reliance on ECDIS).
It is essential that officers remember to cross check the information
displayed by all other means available, especially by looking out the window
and watching the display.
At the same time the officer has to take care of the accuracy of the
integrated navigational sensors.
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ECDIS
International Organizations
To ensure that ECDIS equipment intended for onboard use is seaworthy, it
must pass type approval and test procedures developed by the IEC
(International Electrotechnical Commission) based on the ECDIS
Performance Standards of IMO (International Maritime Organization) and
applying the IHO (International Hydrographic Organization) technical
standards related to the digital data format.
Type approval is a method to show conformance with IMO requirements on
a legal basis. It is initiated and required by all Flag States which are Member
States of the European Union and by many others including United States,
Japan and Australia.
ECDIS type approval is the certification process that ECDIS equipment must
undergo before it will be considered to comply with the IMO Performance
Standards for ECDIS by the international shipping community.
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ECDIS
International Organizations
IHO
IMO
S-52
Performance Standards for ECDIS
IMO Model Course 1.27
SOLAS Convention
STCW
S-57
Specifications for ECDIS
Transfer
S-57
Standard for
App.1 Guidance on Updating
Specifications for ECDIS
Transfer
Digital
App.2 Colour and Symbol
Standard for
App.1 Guidance on Updating Hydrographic
App.3 Glossary of ECDISDigital
Data
App.2
Colour
and Symbol
related
Terms
Hydrographic
App.3 Glossary of ECDISData
related Terms
S-52
IEC
IEC
Publication 61174
Publication 61174
Maritime Navigation and Radiocommunication
Equipment and Systems - Electronic
Maritime
Navigation
Radiocommunication
Equipment
and Systems
- Electronic
Chart Display
and and
Information
System (ECDIS)
– Operational
and performance
Chart
Display methods
and Information
(ECDIS)
Operational and performance
requirements,
of testingSystem
and required
test–results.
requirements, methods of testing and required test results.
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ECDIS
Legacy Aspects – “IMO Performance Standards”
There are two classes of navigational electronic chart system:
1. ECDIS, which meets the IMO/SOLAS chart carriage requirements;
2. ECS (Electronic Chart System), which can be used to assist
navigation, but does not meet IMO/SOLAS chart carriage
requirements.
ECDIS equipment is specified in the IMO “ECDIS PERFORMANCE
STANDARDS” IMO Resolution A817(19) & IMO Resolution
232(82):”Adoption of the revised Performance Standards for ECDIS"; as
follows:
“Electronic Chart Display and Information System (ECDIS) means a
navigation information system which, with adequate back up
arrangements, can be accepted as complying with the up-to-date
chart required by regulation V/19 & V/27 of the 1974 SOLAS
Convention”
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Legacy Aspects – “IMO Performance Standards”
IMO SOLAS V/19:
2.1 All ships irrespective of size shall have:
(…)
2.1.4 nautical charts and nautical publications to plan and display the ship’s
route for the intended voyage and to plot and monitor positions throughout
the voyage; an Electronic Chart Display and Information System (ECDIS)
may be accepted as meeting the chart carriage requirements of this
subparagraph;
2.1.5 back-up arrangements to meet the functional requirements of
subparagraph 2.1.4, if this function is partly or fully fulfilled by electronic
means;*
*An appropriate folio of paper nautical charts may be used as a back-up
arrangement for ECDIS. Other back-up arrangements for ECDIS are
acceptable (see appendix 6 to resolution A.817(19), as amended).
IMO SOLAS V/27:
Nautical charts and nautical publications, such as sailing directions, lists of
lights, notices to mariners, tide tables and all other nautical publications
necessary for the intended voyage, shall be adequate and up to date.
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Legacy Aspects – “Back Up Requirements”
No electronic system is completely failsafe!
IMO Performance Standards therefore require that the ”overall system”
include both a primary ECDIS and an adequate independent back up
arrangement.
IMO added Appendix 6 to the performance standards for ECDIS back up
requirements, lists the required functions and availability requirements of
back up arrangements, including:
• Chart information using the latest official edition that are kept up-to-date
for the entire voyage;
• Route planning capable of performing route planning functions, including
taking over the route plan of the primary system, and adjusting a planned
route;
• Route monitoring enabling take-over of the route monitoring function
originally performed by the primary system, including plotting own ship’s
position and displaying the planned route;
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Legacy Aspects – “Back Up Requirements”
• Voyage recording that keeps a record of the ship’s actual track, including
positions and corresponding times.
The definition of these key functional requirements still leaves open
technical solutions representing adequate back up arrangements. Finally:
A second ECDIS connected to an independent
power supply and a separate GPS position input;
An ECDIS operating in the
RCDS mode of operation;
Back Up
Systems
An appropriate up-todate folio of official
paper charts for the
intended voyage;
A radar-based system called ”Chart-Radar” according
to IMO Performance Standards for Chart Radar;
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Legacy Aspects – “Back Up Requirements”
France
Acceptance of ECDIS:
Applies to all vessels; Maritime Authority provides certification;
Backup Arrangements for ECDIS:
At present the French Administration only authorises paper charts to be used as a
backup to ECDIS;
Acceptance of RCDS:
Applies to all vessels; Maritime Authority provides certification;
IMO or Flag State Notifications:
Règlement annexé à l’arrêté du 23/11/1987, division 221;
Website:
www.mer.gouv.fr
IMO Circular Letter 2666
- Compendium of Flag State ECDIS requirements
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Legacy Aspects – “ENC”
Electronic Navigational Chart (ENC) means the database
standardised as to content, structure and format issued for use
with ECDIS on the authority of government-authorized
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.
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ECDIS
“Numeric Cartography”
There are two types of Numeric Chart:
1. Vector
2. Raster
The difference between them is the data archiving modality.
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Numeric Cartography – “Vector Charts”
(x4,y4)
(x2,y2)
(x2,y2)
(x1,y1)
(x2,y2)
(x1,y1)
Point
Line
(x3,y3)
(x3,y3)
(x1,y1)
Polyline
(x1,y1)
Poligon
ENTITY:
● Points are spatially stored using the coordinates. For example, a twodimensional point is stored as (x1,y1);
● Lines are stored as a series of point pairs, where each pair represents a
straight line segment, for example, (x1, y1) and (x2, y2) indicating a line
from (x1, y1) to (x2, y2);
● Polylines are a connected sequence of lines;
● Polygons are a connected sequence of lines where the first and the last
points are coincident.
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Numeric Cartography – “Vector Charts”
Y
ID
X
Y
ATTRIBUTE
1
1
1.5
…
P1
Numeric Database
X
Each entity type may have one or more attribute. Attributes may describes
quantitative data ranked in 3 level of accuracy:
●
●
●
Ordinal (Ranks: Good, Better, Best);
Interval (Numeric: Age, Income);
Ratio (Scale: Length, Area);
Attributes may describes, also, qualitative data.
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Numeric Cartography – “Vector Charts”
VECTOR DATA
ENTITY
ATTRIBUTE
Qualitative
Point
Poligon
Line
Quantitative
Polyline
Ordinal
Interval
Ratio
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Numeric Cartography – “Vector Charts”
For a building…
ID (unique)
Attribute (qualitative)
Attribute (quantitative - Interval)
ID
X
Y
Type
Area (m2)
Property Nb.
…
1
1
1.5
Industrial
400
40324
…
2
3
3
House
120
3546
…
..
…
…
…
…
Coordinates
Attribute (quantitative - Ratio)
...
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Numeric Cartography – “Vector Charts”
Y
ID
X
Y
ATTRIBUTE
1
1
1.5
…
P1
Numeric Database
X
Vector charts are generally manufactured from scanned hydrographic
office paper charts. The scanned image is then digitised by tracing the lines
and features on the chart.
1. this vectorisation process stores chart features in “layers” (“themes”)
which can be redrawn automatically at an appropriate size as you zoom
into the chart. You can add or remove categories of data such as spot
depths, depth contours, navigation marks, etc.
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Numeric Cartography – “Vector Charts”
2. you can “query” specific chart items (e.g. to get more information on a
navigation light);
3. you can display the chart at a larger scale than the source paper chart
(without image degradation). So it is very important to point out the concept
of Nominal Scale for Numeric Chart.
Remembering that Vector charts are generally manufactured from scanned
hydrographic office paper charts, Nominal Scale is the scale of the source
paper chart.
Pay attention: we can sail, for example, on a chart at 1:5000 with a
Nominal Scale of 1:50000.
The metric information and the chart data are from a 1:50000 scale
chart
4. systems automatically decide on the information to be displayed,
depending on the level of zoom.
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Numeric Cartography – “Vector Charts”
VANTAGE:
● Adding or removing layers of data;
● Zooming and seeing more or less data appear according to the level of
zoom;
● Displaying the chart at a larger scale than the source paper chart;
● Not large data volumes - Compact data structure.
DISADVANTAGE:
● The nature of the vector display is such that the chart data is not
displayed electronically as it was compiled (as a paper document) and the
original cartographic design of the paper chart is lost.
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IHO S57
To ensure that ECDIS function uniformly anywhere in the world, the
information elements contained in the database must be consistent.
It would make non sense for each Hydrographic Office to develop different
types of chart “objects”.
For this reason the IHO (International Hydrographic Organization) develop
an Object Catalogue that described the range of attributes to be assigned
to each object (www.S-57.com).
As the key component of the “IHO Transfer Standard for Digital
Hydrographic Data” (IHO S-57), the object catalogue ensures that the
database for ECDIS, the “Electronic Navigational Chart (ENC)”, is
properly constructed and organized.
So…
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IHO S57
…the “IHO Transfer Data for Digital Hydrographic Data” (usually
abbreviated as IHO S-57) establishes the requirements for producing
an ENC to be used with an ECDIS satisfying the ECDIS Performance
Standard A817(19).
It was completed in November 1996 and published in March 1997 (a new
version has been published in 2000).
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WEND (World-wide Electronic Navigational Chart Data Base)
The Electronic Chart are produced under the authority of a government
organisation (Hydrographic Organization). The user, then, can obtain the
ENC’s from the various HOs directly. This becomes prohibitively
cumbersome if the user engaged on international voyage.
Therefore service providers have been established which collect the ENCs
from different HOs and maybe other sources, to deliver to the end user all
data he needs for his voyage.
A particular problem is to ensure that all official ENCs produced by a
large number of different HOs are of the same quality.
Without an additional intervening mechanism ensuring uniform data quality,
Mariners would be left with inconsistencies between ENCs from different
HOs.
This the background why IHO has developed a concept for a worldwide
official ENC service.
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WEND – ECDIS Data Service
The concept of an official data Service was developed in conjunction with
the IMO requirements to establish a worldwide uniform updating service.
An official ECDIS data service include:
●
Global Uniformity of data: All participants must work in accordance
with the same standard, i.e. S-57 data transfer standard. It must
ensured that ENCs from all producing HOs worldwide exhibit consistent
contents and display.
●
Quickest way from the source to ECDIS: This excludes any
additional levels of processing. That is why the data must come directly
from the originators. The Hydrographic Offices must have strict sharing
of work in close co-operation. This ensures at the same time the global
uniformity of data.
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WEND – ECDIS Data Service
A reasonable solution is to have an arrangement for sharing the work of
setting up and facilitating the provision of a world-wide ECDIS data service
based upon agreed upon standard.
This arrangement was established by the IHO as the World-wide
Electronic Navigational Chart Data Base (WEND).
The purpose of WEND is “to ensure a world-wide consistent level of high
quality, updated official ENCs trough integrated services that support chart
carriage requirements of SOLAS Chapter V and requirements of the IMO
Performance Standards for ECDIS”.
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WEND – ECDIS Data Service - RENC
WEND consists of two components to achieve its purpose:
●
●
A charter describes the principles governing the co-operation. This
includes the following provisions:
o
By definition, the organization responsible for hydrographic survey
of an area is also responsible for the ECDIS data;
o
The relevant ECDIS standards, especially S-57 Edition 3 must be
observed;
o
The rules and responsibilities for producing and validating the data.
So called Regional Electronic Chart Co-ordinating Centres
(RENC) which “are organisational entities where IHO members have
established co-operation amongst each other to guarantee a worldwide consistent level of high quality data, and for bringing about cocoordinated service with official ENCs and updates to them”.
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Numeric Cartography – “Raster Charts”
An exact replica of the paper chart (scanner).
The Raster Image is subdivided in pixels, in a matrix of n lines and m
columns.
Each pixel has a homogeneous and not sub divisible contents.
Pixel
RADIOMETRIC RISOLUTION
● CROMATIC RISOLUTION (BPP)
●
●
GEOMETRIC RISOLUTION (DPI)
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Numeric Cartography – “Vector and Raster Charts”
Raster
Vector
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Numeric Cartography – “Official Charts”
Official electronic chart data and private chart data
Official electronic chart data are of two general types:
• Electronic Navigational Charts (ENC);
• Raster Navigational Charts (RNC).
The inner construction of ENCs and RNCs is fundamentally different:
• ENCs are vector charts;
• RNCs are raster charts.
The term “Official”, indicates that those chart data have been produced
under the authority of a government organisation – in contrast to private.
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Numeric Cartography – “ENC”
ENC means the database, standardized in the content, structure and
format, issued for use with ECDIS on the authority of governmentauthorized Hydrographic Offices.
ENCs are vector charts compiled from a database of individual georeferenced objects from Hydrographic Office’s archives including existing
paper charts.
ENCs have the following attributes:
• ENC content is based on source data or official charts of the responsible
Hydrographic Office;
• ENCs are compiled and coded according to international standards;
• ENCs are referred to World Geodetic System 1984 Datum (WGS84);
• ENC content is the responsibility and liability of the issuing Hydrographic
Office;
• ENCs are issued only by the responsible Hydrographic Office;
• ENCs are regularly updated with official update information distributed
digitally.
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Numeric Cartography – “ENC – S52/S57”
In conjunction with the development of IMO Performance Standards for
ECDIS, the International Hydrographic Organization has developed
technical standards related to the digital data format, specifications for
ECDIS content and display, and data protection.
• IHO Special Publication 52 (S-52): includes appendices describing the
means/process for updating, colour and symbol specifications, and a
glossary of ECDIS-related terms.
• IHO Special Publication 57 (S-57): includes a description of the data
format, product specification for the production of ENC data, and an
updating profile.
Both IHO S-57 and S-52 are specified in the IMO Performance
Standards for ECDIS.
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Displaying ENCs by means of the Presentation Library
ENCs don’t contain any explicit visualisation items. An ENC contains an
abstract description of geographic entities but does not contain any
presentation rules.
All presentation rules to get ENC’s content displayed are contained in a
separate software module – the so called “Presentation Library”.
Both the Geo-referenced object contained in the ENC and the fitting
symbolization contained in the Presentation Library are linked to each
other only in the very moment of their call up for display.
The definition of the Presentation Library for ENCs is contained in Annex A
of the IHO Special Publication S52, Appendix 2 “Colours & Symbols
specifications for ECDIS”.
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Displaying ENCs by means of the Presentation Library
ENC
PRESENTATION LIBRARY
Description of Geographic Entities
(S57)
Contains all presentation rules
(S52)
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Numeric Cartography – “ENC/S63”
A majority of all ENCs are only made available to the end-users in a
protected form compliant with the IHO S-63 Data Protection scheme.
The S-63 protection scheme defines a mechanism for encrypting ENC
information and applying a digital signature to enable authentication of the
chart data by the end-user. The end-user will require a decryption key to
access and view the ENC data protected by the scheme.
Each ENC chart is encrypted with a different key, and the decryption keys
are issued to specific end-user systems and can consequently not be
exchanged or shared by different systems.
A majority of all ECDIS and ECS suppliers have developed support for IHO
S-63 and can read protected ENCs.
A few nations distribute their ENCs without using encryption; all ECDIS
systems are able to access and display these ENCs.
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Numeric Cartography – “SENC”
An ECDIS does not process the ENC content directly for the matter of
display. ENCs in S-57 format are optimised to absorb the Hydrographic
object information but this structure is not adequate for the fast generation
of the resulting computer image on the screen.
In order to get efficient data structures that facilitate the rapid display of
ENC data, ECDIS firstly converts each ENC from S-57 ENC format into an
internal format called SENC (System ENC) which is optimised for chart
image creating routines.
Such routines are not standardised; they are part of the individual software
know-how of the ECDIS manufacturers. Consequently the SENC format
differs between the ECDIS of different manufacturers. In contrast to the
common uniform ENC format the SENC format is proprietary for each
ECDIS manufacturer.
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Numeric Cartography – “SENC”
ENCs in S-57 format have to be translated into the internal data format or
SENC (System Electronic Navigational Chart) used by the ECDIS before
they can be displayed.
The main SENC formats are C-Map's CM-ENC (CM-93/3) format
supported by over 20 ECDIS manufacturers.
The most noticeable effect is the difference in installation and updating
time. Here are the results of tests from “10 Things They Should Have Told
You About ECDIS”:
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Numeric Cartography – “SENC”
Comparison between S-57 ENC and SENC installation times
(all available cells, Sept 06)
S-57 ENC format:
Disk copying (5 base CDs) 1.5 hours
Decryption, verification and installation 11.2 hours
Total 12.7 hours
Apply Update CD 4.03 hours
CM-ENC SENC format:
Disk copying (1 DVD) 13 mins
Apply licence 5 mins
Total 18 mins
On line update A few minutes
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Numeric Cartography – “ENC/N.P.N.S.R.”
During production, ENCs are assigned a compilation scale based upon the
nature of the source data they are based on, and are allocated to a
navigational purpose band related to this. As shown in the table below
there are 6 navigational purpose bands (scale ranges are indicative only).
Navigational Purpose Name Scale Range :
1 Overview
2 General
3 Coastal
4 Approach
5 Harbour
6 Berthing
>1:1 499 999
1:350 000 – 1:1 499 999
1:90 000 – 1:349 999
1:22 000 – 1:89 999
1:4 000 – 1:21 999
< 1:4 000
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Numeric Cartography – “ENC Code”
Each ENC is identified by an 8 character identifier e.g. FR501050:
• The first two characters indicate the producer e.g FR for France, IT for
Italy (a complete list of producer codes is included in the IHO standard S62).
• The third character (a number from 1 to 6) indicates the navigational
purpose band.
• The last 5 characters are alpha- numeric and provide a unique identifier.
A Chart with a different code is an unofficial chart.
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Numeric Cartography – “ENC Code”
ECDIS distinguishes an ENC from unofficial data. When unofficial data is
used, ECDIS informs mariners that they must navigate by means of an
official, up to date, paper chart by a continuous warning on the screen.
If unofficial data is shown on the ECDIS display, its boundary is to be
identified by a special line style. This boundary is visualized as a “onesided” RED line with the diagonal stroke on the unofficial side of the line.
ENC
Unofficial data chart
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Numeric Cartography – “Updating ENCs”
In principle the generation and distribution of regular updates uses identical
organisational structures as for the production and distribution of ENCs
described above. Their frequency is usually synchronised with the chart
corrections promulgated with national Notice to Mariners for the affected
sea areas.
Updates may reach the ship via different ways depending from the
capabilities of the service provider and the communication facilities
onboard:
• On data distribution media, e.g. CD;
• As e-mail attachment via SATCOM; and
• As broadcast message via SATCOM plus additional communication
hardware.
A number of ENC service providers already have updating services using
e-mail and web and other means; details may be obtained from ENC
distributors.
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Numeric Cartography – “Updating ENCs”
Updates to ENCs are sequential, and the sequence is unique to each ENC.
During the updating process ECDIS always checks that all updates in the
sequence have been applied. If an update is missing then the ECDIS will
indicate this; it is not possible to load later updates until the missing update
is applied.
The ECDIS maintains a list of updates applied and the date of application.
Port State Control officers may use the ECDIS listing to ensure that ENCs
are being kept up to date in accordance with SOLAS V Regulation 27.
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Numeric Cartography – “ENCs Coverage”
The International Hydrographic Organisation (IHO) provides an interactive web
catalogue (http://services.ecc.as/ihocc/public) displaying the status of worldwide
ENC production. This system has pointers for guiding users to ENC suppliers and
distributors.
It is also possible to download the ENC catalogue information from here as a
comma separated file.
ECS
- ELECTRONIC CHART SYSTEM
ECDIS - ELECTRONIC CHART DISPLAY AND INFORMATION SYSTEM
Data Base
Certification
Status
Official Certificate
issued by Maritime
Administrtion
ECDIS
System not
accepted as legal
equivalent of
paper charts
ECS
Updating System
Official, regular
updading service
Electronic
Navigational
Charts
ENC
Back-up
Arrangements
Adopted by
Maritime
Administration
No regular updates
ECS
International
Standards
IMO A.817/19
IHO S52, S57,
IEC 61174
Electronic Charts
System
Other data base
Other
ECS
ECS
ECS
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Numeric Cartography – “ENC”
In order to replace paper charts:
The chart data in use must be official - ENCs
where these are available.
What to do in areas without ENC coverage?
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Numeric Cartography – “RNC/RCDS”
RNC means “Raster Navigational Chart”. RNCs are digital raster copies of
official paper charts conforming to IHO Product Specifications RNC (S-61).
By definition RNCs can only be issued by, or on the authority of, a national
Hydrographic Office.
RNCs have the following attributes:
• RNCs are a facsimile of official paper charts;
• RNCs are produced according to international standards;
• RNC content is the responsibility of the issuing Hydrographic Office; and
• RNCs are regularly updated with official update information distributed
digitally.
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Numeric Cartography – “RNC/RCDS”
In 1998 the IMO recognised that it would take some years to complete the
world’s coverage of ENCs.
As a consequence IMO ECDIS Performance Standards were amended
adding a new optional mode of operation of ECDIS, the Raster Chart
Display System (RCDS) mode.
In this mode RNCs can be used in ECDIS to meet SOLAS carriage
requirements for nautical charts. However, this is only allowed if approved
by the Flag State. The intention of those changes was to allow the ECDIS
to operate as far as possible on official chart data; ENCs where they were
available and RNCs to fill in the gaps.
IMO took note of the limitations of RNCs as compared to ENCs (see IMO
SN Circular 207 at Annex), and the revised ECDIS Performance Standards
require that the ECDIS must be used together with “an appropriate folio of
up to date paper charts” for the areas where RCDS mode is employed.
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”
The intention was to allow the number of paper charts carried by a vessel
to be reduced where RCDS mode was employed, but only to a level
compatible with safe navigation. No definition of an “appropriate folio” was
provided by IMO and consequently different Flag States developed
individual interpretations.
As there is no common interpretation of the term “appropriate” ship owners
should consult their Flag State as to whether RCDS mode is allowed and
under what conditions.
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”
There are two official raster chart formats (RNC):
1. ARCS (UK HO) and Seafarer (Australian HO) both produced in the UK
HO’s proprietary HCRF format. ARCS is updated weekly with the same
information as the weekly Notice to Mariners used to correct BA paper
charts. Seafarer is updated monthly on a similar basis.
2. BSB raster charts contain all the detail found in NOAA paper charts,
with updates published every 30 days. Weekly Notice to Mariner
updates will be available in the second quarter of 1998. These will be
distributed via the Internet and will be completely in-sync with the US
Coast Guard, NIMA and Canadian notices (free from NOAA web site).
+ CHS
ECS
RCDS -
- ELECTRONIC CHART SYSTEM
Certification
Updating System
RASTER CHART DISPLAY SYSTEM
+ an appropriate portfolio of up to date paper nautical charts
Data Base
Official, regular
updading service
Raster
Navigational
Charts
RNC
Status
System accepted as
legal equivalent of
paper charts
(interim solution)
ECDIS
RCDS
System not
accepted as legal
equivalent of
paper charts
ECS
Back-up
Arrangements
Any
No regular updates
ECS
International
Standards
IMO A.817/19
Appendix 7
Other data base
ECS
IHO S-61
Electronic Charts
System
Other
ECS
ECS
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”
ECDIS COURSE - Italian Maritime Academy Technologies
ECDIS
Numeric Cartography – “RNC/RCDS”