An
electronic chart display system is a general term for all electronic
equipment that is capable of displaying a vessel’s position
on a chart image on a screen. There are two classes of electronic
chart display systems. The first is an ECDIS (Electronic Chart Display
and Information System), which can meet IMO/SOLAS chart carriage
requirements. The second is an ECS (Electronic Chart System), which
can be used to assist navigation, but does not meet IMO/SOLAS chart
carriage requirements. |
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| Compatible
Electronic Chart Systems: |
A
number of systems have been tested if they are compatible with data
in S-63x or directENC format vended by ChartWorld.
S-63x stands for S-63 data (encrypted S-57 data) are contained in
zip archives with file extension '*.ZIP.S63'. These zip archives
containing some additional information helpful for data management.
The corresponding ChartKey file has the extension '*.ZIP.PRM' and
holds the file 'permit.txt' which contains the chart permits for
the ordered vector charts and holds also some additional files containing
the list of the relevant charts and the used 'ENC User permit'.
directENC is the specific SevenCs SENC format. 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, so that each ECDIS/ECS firstly converts
each ENC from S-57 format into its proprietary internal format called
SENC – System ENC – which is optimised for chart image
creating routines. directENC charts are just pre-converted S-57
data to speed up the data import substantially. |
ECDIS
(Electronic Chart Display and Information System):
|
ECDIS
is a ship borne navigational device and as such it is the responsibility
of IMO. It must support the whole range of navigational functions
that make use of the characteristics of the chart data and their
specific presentation.
Within the ECDIS, the ENC database stores the chart information
in the form of geographic objects represented by point, line and
area shapes, carrying individual attributes, which make any of these
objects unique. Appropriate mechanisms are built into the system
to query the data, and then to use the obtained information to perform
certain navigational functions (e.g. the anti-grounding surveillance).
The use of ENCs in a tested, approved and certified ECDIS and with
appropriate back up arrangements, is the only paperless chart option
for vessel navigation. |
ECS
(Electronic Chart System): |
ECS
is a navigation information system that electronically displays
vessel position and relevant nautical chart data and information
from an ECS Database on a display screen, but does not meet all
the IMO requirements for ECDIS and is not intended to satisfy the
SOLAS Chapter V requirements to carry a navigational chart.
All systems, which are not tested to show compliance with the ECDIS
Performance Standards, can be generically designated as ”Electronic
Chart Systems” (ECS). An ECS may be able to use either ENCs,
RNCs or other chart data produced privately and could have functionality
similar to ECDIS. |