The primary factor that influences the portrayal e-navigation information is the operational situation. In turn, what information is required depends on the voyage requirements, situation needs, operational perspective (shipborne or shore-based), and levels of information.
Voyage Requirements
The type or amount of e-navigation-related information that will be portrayed by shipborne or shore-based users falls into two main categories: to strategic overview and tactical.
Strategic overview is associated with maintaining overall situational awareness within the surrounding areas. This can include both monitoring and active engagement.
Tactical involves more direct action and decision-support within the immediate or designated area.
Situation Needs
Current situation includes the various phases of navigation during a voyage or can be related to the prevailing conditions. Examples of different navigation phases include open-ocean, coastal, and approach. Prevailing conditions include, daytime vs. nightime transits, calm vs. stormy weather conditions, good vs. poor visibility, light vs. heavy vessel traffic, etc.)
Regardless of the current situation, the Task-at-Hand can be the determining factor in what information is crucial to making informed decisions. This includes time-critical information necessary for grounding avoidance, collision avoidance, or maintaining overall situational awareness.
Shipborne-perspective
The International Chamber of Shipping “Bridge Procedures Guide” 8 provides a useful description of the personnel, activities, equipment, and procedures that “reflect best navigational practice on merchant ships operating today, in all sectors and trades.” As explained in the Forward to the publication, the new (4th) edition has been revised to address the increasing use of modern electronic navigation and charting systems. In particular, it is pointed out that “increased sophistication brings its own dangers and the need to precautionary measures against undue reliance on technology.”
Shore-based
The IALA VTS Manual9 (5th Edition, 2012) is a comprehensive guide to Vessel Traffic Services (VTS). As described in the Introduction, “the contents are aimed at a wide readership to encompass all who are in any way involved in the provision, operation, and effectiveness of VTS, including those with management responsibility at national level, and those who deliver services to the mariner.” For both shipborne and shore-based users, the manual provides useful information on the type of VTS service and functions, VTS-related equipment, and roles and responsibilities of VTS personnel.
There are at least three different levels of e- navigation related information, both at the present time and likely in the future10:
1) Required by IMO
2) Required by Flag or Port States in national waters
3) Innovative or Future Applications
Level 1 - Required by IMO
This is equipment or systems that are required to meet mandatory carriage requirements (e.g., under SOLAS IV and V). At the present time, this includes the following:
ECDIS
Radar
AIS
INS
GMDSS (or equivalent)
Level 2 – Might be required by flag or port states in national waters
Potentially, there may be certain types of equipment, systems, or operational capabilities that would be required for certain areas. At this time, there are no mandatory requirements. However, in the near future there could be situations where ‘e-navigation capable’ vessels are recognized as having an additional operational capability that enables them to safely proceed in navigation-challenged areas. Possible examples of these areas include the Torres Strait (Australia), The Sound (strait between Sweden and Denmark), and Arctic regions (Canada, Denmark, Norway, Russia, and USA).
Level 3 - Innovative or Future Applications
In recent years, there have been an increasing number of government-sponsored projects that have been conducted that e-navigation relevance. Some examples include:
ACCSEAS (Accessibility for Shipping, Efficiency, Advantages and Sustainability)
BLAST (Bringing Land and Sea Together)
EfficienSea (Efficient, Safe and Sustainable Traffic at Sea)
MARNIS (Maritime Navigation and Information Services)
MONALISA Project (Motorways & electronic Navigation by Intelligence at Sea)
MEH (Marine Electronic Highway)
St. Lawrence River (Canada) e-Navigation Testbed
There are also a number of commercially-available, innovative mobile devices or applications (e.g., smart phone, tablets, etc.) that are being used to ‘improve’ navigation practices.
Non-compulsory purchase and use
Minimum statutory approval to show compliancy with the essential requirements of e-navigation and compatibility with other applications.
Allow innovation and fast evolution
Aimed at providing commercially-attractive packages
Fuel reduction
Navigational improvements
Improved company-level reporting
Dynamic under-keel clearance
Annex A contains a compilation of examples of innovative applications that could become a component of future e-navigation operations. A more detailed description of each of the applications is available on the IALA website.
BASIC GUIDANCE ON PORTRAYAL Six basic ways
There are six (6) basic ways to visually portray any type of e-navigation information.
alpha-numeric
graph
point, line or polygon
symbol
geo-spatial
imagery
The following sections provide basic, common sense guidance with an example for each.
Alpha-numeric
Unless there is a need to display pre-formatted text or numbers, use a ‘sans-serif’ font. To avoid ambiguity, use lower-case lettering for actual words (e.g., radar) and capital letters only for abbreviations (e.g., AIS for Automated Identification System).
Graph
In some situations, a time-series graph may be a preferred instead of a table format. In particular, is a useful way to show both predicted and real-time information (e.g., water levels). It is also a useful means to indicate trends (e.g., rising or falling water levels).
Point, line, or polygon
This type of ‘vector data’ is often displayed as an overlay on chart or map-related background. An Area Notice that is transmitted via AIS Application Specific Message is one example.
Symbol
Similar to the guidance contained in IMO SN.1/Circ.290, the following guiding principles apply to the display of symbols or icons:
Use consistent symbology across all displays
Uniqueness – only one possible meaning
Non-ambiguous – ability to determine differences (i.e. distinct)
Intuitively obvious – an easily recognized symbol, icon, or pattern
Have a basic symbol for different categories. Further attributes should be
enhancements (not changes) to the basic symbol.
Geo-spatial
Many types of geo-spatial information are best provided in the form of a map or chart. The electronic chart display of an ENC in ECDIS is one example. Another example would be a radar display with chart facilities.
Imagery
This is a broad category that includes various types of images. A still photograph of a fixed or floating Aid to Navigation (AtoN) is one example. Other examples include radar or satellite imagery of sea ice weather conditions. A video recording/replay of a past or simulated voyage is type of dynamic imagery. There is also increasing interest in the use of 3-D imagery.
In order to achieve ‘harmonization’ in the portrayal of e-navigation information for both shipborne and shore-based e-navigation users, there are several guiding principles to consider:
The data content and format of e-navigation related data should be similar (e.g., GPS/DGPS, AIS ASMs, ENCs, etc.). However, how the data is displayed as ‘information’ depends on the particular tasks, function, and needs of the user.
There should be a means to achieve a similar portrayal of e-navigation information on key equipment/systems (e.g., ECDIS and radar). One possible means of achieving this is to have a default e-navigation portrayal mode that could be used to portray navigation-related information in a similar manner to that of shipborne displays.
The “portrayal of e-navigation information onboard ships or ashore does not necessarily have to be identical.”11 However, there is benefit to all users if information is displayed in a consistent and unambiguous manner. This includes the use of standard symbology, icons, and colour schemes.
With new types of e-navigation related information becoming available, there will a tendency to add more information to existing navigation displays (e.g., ECDIS and radar). Displaying too much supplemental information can obscure critical information or lead to confusion.
CURRENT PRESENTATION/DISPLAY STANDARDS
At the present time, there is no 'formal' list of what equipment/systems/services are currently considered (or will become) components of e-navigation -- either shipborne or shore-based. As such, the following list is based on what is mentioned in various SOLAS V/19 & 20, IMO MSC, IMO NAV12, and IALA e-navigation related documents. These equipment/systems/services are also are mentioned in IMO e-navigation 'Gap Analysis' process13. These standards should be considered ‘prescriptive' in terms of what is required. For each standard, specific mention is made of those sections that have particular relevance to presentation, display, or portrayal requirements for shore-based applications. To aid this process, relevant sections are highlighted in grey colour.
ECDIS
IMO MSC.232(82), Revised performance standards for electronic chart display and information systems (ECDIS), 5 December 2006
This performance standard applies to ECDIS equipment carried on all ships including a dedicated stand-alone workstation or a multi-function workstation as part of an INS. Requirements for structure and format of the chart data, encryption of chart data as well as the presentation of chart data are based on relevant IHO standards (e.g., IHO S-57 for ENC data and IHO S-52 for presentation/display of chart-related information). In addition to the general requirements set out in IMO Res. A.694(17)14 and the presentation requirements set out in resolution MSC.191(79), ECDIS equipment must meet the requirements of this performance standard, as well as follow the relevant guidelines on ergonomic principles.15
Section
Scope of ECDIS
Application of these standards
Definitions
Provision and updating of chart information
Display of SENC information
Scale
Display of other navigational information
Display mode and generation of the neighbouring area
Colours and symbols
Display requirements
Routing planning, monitoring and voyage recording
Calculations and accuracy
Performance tests, malfunctions alarms and indications
Back-up arrangements
Connections with other equipment
Power supply
IHO S-52, Specifications for chart content and display aspects of ECDIS Edition 6, March 2010
As specified in Section 9.1 of the IMO Performance Standard for ECDIS, IHO recommended colours and symbols (i.e., IHO S-52) is used to represent chart-related information on ECDIS. This is intended to ensure: consistency in base and supplementary levels of display for ENC data; standards of symbols, colours and their standardized assignment to features; scale limitations of data presentation; and, appropriate compatibility with paper chart symbols as standardized in the Chart Specifications of the IHO.
Further, use of IHO S-52 is intended to ensure that:
the display is clear and unambiguous
there is no uncertainty over the meaning of colours and symbols on the display, [by] establishing an accepted pattern for ECDIS presentation that becomes familiar to mariners and so can be recognized instantly without confusion.
IHO S-52 contains several parts, and all pertain to the presentation/display of chart and navigation-related information :
Main Document – This describes the Specifications for Chart Content and Display Aspects of ECDIS the in relatively general terms (i.e., methods and requirements).
Annex A – The Presentation Library is separate document (see further explanation below), and provides specifies the colours, symbols, symbolization instructions, etc. together with guidance on how an ENC should be displayed on ECDIS. This annex has several components:
Part I contains chart objects, and an addendum which is a paper-based description of the symbol library as graphics.
Part II contains [recommended] Mariner’s Navigational Objects (e.g.,. own ship symbol, tracks, waypoints, time tags, etc.)
The ECDIS Chart 1 is also included with the Presentation Library as a graphic file, and is also available as a collection of the varying objects contained in a special cell in S-57 format containing generic feature objects.
Annex B - Specifies procedures for initial colour calibration of displays and the verification of that calibration.
Annex C - Specifies a procedure for maintaining the calibration of displays.
IHO S-52 Annex A, IHO ECDIS Presentation Library Ed.3.4, January 2008
This specification provides the details and procedures for implementing the display specifications contained in S-52. It includes a full description of the symbol library for use in ECDIS. It is published separately from the Main Document, and is available on CD-Rom. Both the Main Document and Annex A are maintained by means of Maintenance Documents (MDs) which are produced from time to time, and are available on the IHO website (www.iho.int). The MDs contain required amendments to S-52 and/or the PresLib, and are classified as "immediate" or "deferred" depending on their importance for the safety of navigation.
IEC 61174, Maritime navigation and radiocommunication equipment and systems – Electronic chart display and information system (ECDIS) – Operational and performance requirements, methods of testing and required test results, Edition 3, October 2010
This standard specifies the performance requirements, methods of testing and required test results of equipment conforming to performance standards adopted by the IMO in resolution MSC.232(82). This standard is also associated with IMO resolution A.694(17) and IEC 60945. This standard includes extracts from IHO S-52 when they are applicable to ECDIS. As stated in Section 1 (Scope), The requirements of this standard are not intended to prevent the use of new techniques in equipment and systems, provided the facilities offered are not inferior to those stated.
This standard provides considerable detail about what is required to conform to ECDIS-related standards. The following sections are directly related to presentation, display or portrayal of chart and navigation-related on ECDIS equipment.
4 Minimum operational and performance requirements
4.3 Display of SENC information
4.5 Scale
4.6 Display of other navigational information
4.7 Display mode and generation of the neighbouring area
4.8 Colours and symbols
4.9 Display requirements
5 Requirements contained in IHO special publications
5.1 Content and structure of chart data
5.2 Priority of chart display
5.3 Display of chart information
5.3.1 Scale and navigation purpose
5.3.2 Text
5.3.3 Units and legend
5.4 Display functions
5.4.1 Object information
5.4.2 Navigational information
5.4.3 Safety contour
5.4.4 Navigational calculations
5.5 Supplementary display functions
5.5.1 Additional mariner’s information
5.5.2 Additional non-HO information
5.5.3 Tidal adjustment
5.6 Use of the presentation library
5.7 Display characteristics
5.8 Performance requirements
5.8.1 Redraw
5.8.2 Resolution
5.8.3 Number of colours
5.8.4 Brightness and contrast
5.9 Ergonomic requirements
6.5 Initial data tests
6.5.1 Presentation library
6.5.2 ENC
6.6 Accuracy
6.7 Visual requirements
6.7.1 Symbols
6.7.2 Units and legend
6.7.3 Colour table
6.7.4 Resolution
6.7.5 Display characteristics
6.8 Functional requirements
6.8.1 Standard display
6.8.2 Display base
6.8.3 All other information
6.8.4 Display priorities
6.8.5 Additional display functions
6.8.6 Scale and navigation purpose
6.8.7 Mode and orientation
6.8.8 Safety contour
6.8.9 Safety depth
6.8.10 Object information
6.8.11 Navigation related functions
6.8.12 Position integration
6.8.13 Radar and plotting information
6.8.14 Loading of corrupted data
6.8.15 Automatic updates
6.8.16 Manual updates
6.9 Operational requirements
6.9.1 Ergonomic principles
Annex A - SENC information to be displayed during route planning and route monitoring
Annex B - Navigational elements and parameters
Annex C - Areas for which special conditions exist
Annex D - Alarms and indicators
Annex E - Navigational symbols
E.1 Introduction
E.2 Symbols
E.2.1 Symbol definition format
E.2.2 Route monitoring and route planning symbols
Annex F (normative) ENC test data set
F.1 General requirements
F.2 Data subset A – ENC
F.2.1 Complex area
F.2.2 Small-scale data
F.2.3 Data content
F.2.4 Alarms and indications
F.2.5 Alarms and indications: large-scale data
F.2.6 Mathematical calculations
F.2.7 Graphical representations
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