International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 5

Number 1

March 2011

1 THE LANDSCAPE OF ELECTRONIC

NAVIGATION

In different organizations, involved in safety of life

at sea, aspects of navigating a vessel from port to

port are discussed. The importance of navigation is

highlighted by the International Maritime Organiza-

tion (IMO) in the “Safety Of Life at Sea” (SOLAS)

regulation, especially in chapter V. The discussion

on safety of navigation is key to the IMO Maritime

Safety Committee (MSC). Because MSC realized

this important aspect of SOLAS, it created the

“Safety of Navigation” Sub-Committee (NAV) fo-

cusing on exactly this.

The discussion in NAV centered for years around

the “Electronic Chart Display Information System”

(ECDIS). In 2010 MSC, on request of NAV, has ap-

proved a new regulation, which outlines the man-

dates of ECDIS on defined SOLAS-Class ships in a

phased-in approach starting 2012 and reaching all

desired vessels by 2018.

While IMO focuses on the regulatory aspects to

ensure and improve safety of navigation at sea, the

International Hydrographic Office (IHO) since its

establishment in 1921 focuses on the cartographic

aspects of safety of navigation as well as associated

activities.

On its websites the IHO defines its goals as fol-

lows:

“The object of the Organization is to bring about:

− The coordination of the activities of national hy-

drographic offices,

− The greatest possible uniformity in nautical charts

and documents,

− The adoption of reliable and efficient methods of

carrying out and exploiting hydrographic surveys,

− The development of the sciences in the field of

Hydrography and the techniques employed in de-

scriptive oceanography (www.iho-ohi.net).

A Harmonized ENC Database as a Foundation

of Electronic Navigation

M. Bergmann

Jeppesen, a Boeing Company, Frankfurt Am Main Area, Germany

ABSTRACT: The current discussion on the future of electronic navigation is focusing on the expansion of

ECDIS by integrating additional data streams, like AIS or real-time tide information. While this are important

aspects, which will be touched on in the paper, it is important to note that the ENC data layer is the necessary

data layer to enable advanced data display.

The current focus on ENC production has a limited view on coverage within scale bands and on datum code.

While this allows concentrated efforts to produce the necessary country coverage to meet the timeframe of the

IMO ECDIS mandate, future mariners will require a more solid basis of chart data for their electronic naviga-

tion needs. The IMO e-Navigation discussion and the discussions in related the IALA e-Navigation Commit-

tee are starting to join efforts with the new IHO S-100 and S-101 standards as well as the developing S-10X

series of standards. The Hydrographic community needs to take that in account when preparing for the future

of electronic navigation to increase safety of navigation in a rapidly changing environment with larger ships

and more traffic in areas with specific navigational challenges.

The paper will focus on the following topics:

– The ENC data layer as the basis of electronic navigation,

– Closing gaps and overlaps in ENC coverage by adjusting cell boundaries,

– Moving from a cell based data structure to a seamless database structure,

– Integration of Scale-Independent and Scale-Dependent objects,

– Adaption of harmonized and flexible data models – an S-10X outlook,

– Enabling integration of advanced data streams – an e-NAV outlook.

Table 1 IMO Timetable for ECDIS carriage requirements – from “ECDIS – What you need to know”, Jeppesen

Key components of these objectives are the

standards for the “Electronic Nautical Charts”

(ENCs). Especially the current S-57 standard defines

those ENCs, which are, per ECDIS performance

standard, the only vector data sets, which allow op-

erating an ECDIS in its so called ECDIS mode, and

as such to perform primary navigation with electron-

ic systems.

IMO has looked at the Hydrographic Offices

(HOs) around the world, represented by IHO, to

provide adequate ENC coverage before adapting the

ECDIS mandate. The IHO has confirmed to IMO-

MSC and IMO-NAV that by 2012 adequate ENC

coverage will be available.

All of the above highlights that both IMO as well

as IHO see ENCs in ECDIS as the foundation and

primary data set for electronic navigation.

2 THE “E-NAVIGATION” CONCEPT

Following its initiative on ECDIS, IMO has

launched another initiative: “e-Navigation”. The “e-

Navigation Correspondence Group” identifies de-

tails on “enhanced Navigation”, which is intended to

integrate shore based and ship based systems and da-

ta streams to increase situational awareness in any

phase of sailing and as such increase Navigational

safety even further. The discussion circles around

concepts like integrated AIS (Automated Identifica-

tion System), different system overlays on board, au-

tomated information exchange between shore and

ship, like sharing Vessel Traffic System (VTS) data

and so on.

The IMO e-Navigation development and the dis-

cussions in the related e-Navigation Committee of

the International Association of Marine Aids to Nav-

igation and Lighthouse Authorities (IALA) are start-

ing to join efforts. Within the last few months vari-

ous working groups have taken great efforts to align

the development in IHO, IALA and IMO and to

harmonize the view of the future of electronic and

enhanced navigation. In those meetings the organi-

zations, the industry and individual expert contribu-

tors could reach agreement that the new IHO S-100

and S-101 standards and concepts as well as the de-

veloping S-10 X series of standards should be used

to build the bases for the new marine data models.

This includes the usage of the IHO “GI-Registry”,

the “Geographical Information Registry”, which

supports the harmonization of GIS-Data Models

across the maritime industry and its initiatives. This

development provides the necessary harmonized

platform for integrated systems. The hydrographic

community starts to take the initiative preparing for

the future of electronic navigation to increase safety

of navigation in a rapidly changing environment

with larger ships and more traffic in areas with spe-

cific navigational challenges.

The concept of e-Navigation is evolving the un-

derstanding that future navigation will need constant

innovation, and as such will need to change how

performance standards are handled. It is widely un-

derstood that the current ECDIS performance stand-

ard is restricting innovation. Its update and certifica-

tion concept is not geared up to meet the needs of e-

Navigation.

The currently being developed new concept de-

fines a framework in which a growing number of da-

ta streams are integrated and harmonized to allow

the creation of the necessary information for in-

creased Situational Awareness in an environment of

growing complexity.

The on board and on shore systems to be devel-

oped within this framework will have to create a

compelling need for their usage by increasing safety

and security of navigation (compelling need for

coastal administration) and improved efficiency of

voyage (compelling need for ship owners and opera-

tors).

The dominant argument unifying all stakeholders

to move towards common structures and towards the

IHO originated model is the fact that the implemen-

tation of S-100 and its related standards is well un-

derway and will materialize shortly. As a conse-

quence ENCs will follow this data structure, so are

associated data streams, like “Inland ENCs” or “Ma-

rine Information Overlays”. As all stakeholders

agree that the ENC layer will build the foundation of

any kind of advanced navigational systems, it was a

natural development to try to align other data stream

with this foundation. But looking from the other side

this development again verifies that ENCs, or better

Hydrographic Vector Chart Data Layers, are the

necessary ingredients for any navigational display

now and in the foreseeable future.

3 MIGRATION FROM A “CHART CENTRIC”

TO A “SITUATIONAL CENTRIC” CONCEPT

The traditional hydrographic work to create the nec-

essary tools for mariners to navigate safely is utiliz-

ing classic cartographic concepts.

An early chart from the year 1603 illustrates that

cartographic art work is used to allow the knowl-

edgeable navigator gaining sufficient information for

a safe passage.

In the “paper” or “analog” world, this has devel-

oped over hundreds of years as the best practice to

transport the necessary information. The current pa-

per charts of HOs around the world are in most cases

beautiful artwork, well developed to help navigate

ships.

Even in the electronic world, this concept started

to materialize with the usage of “Raster Charts” in

displays, with ARCS (Admiralty Raster Chart Ser-

vice) as a prominent example. The stakeholders then

realized that the full potential of electronic naviga-

tion cannot be explored with this raster charts. Vec-

tor cartography showed new opportunities of in-

creased situational awareness by utilizing

capabilities of data links, full zooming capabilities

without “fading” and a growing number of other ad-

vantages. While the first vector charts had been de-

veloped unregulated by key stakeholders in the in-

dustry, the now already often mentioned ENCs have

made their way on bridges of SOLAS class ships as

the only official electronic navigational chart.

While this development was the necessary next

step in electronic navigation, the current ENCs,

based on the S-57 standard, are not reaching far

enough. These ENCs are “cell based”, which means

they are still looking at a certain “chart”, a defined

rectangle on the globe. As a consequence, what is

today offered is not a real “Hydrographic Database”,

but rather a collection of associated charts in a cen-

tral data repository. The HOs try to harmonize the

cells to create a kind of “seamless” appearance in the

ECDIS display. But as the view of each cell in the

creation is still often a “chart by chart” view, this

harmonization is not always successful. An addition

complication in harmonizing such a chart centric

view on ENCs is the fact that the current system is in

general focusing on a “scale band” concept. Here the

hydrographic data is composed by cartographers in a

certain cell to be for optimal use on a certain zoom

level. As this is on a cell by cell and scale band by

scale band level, harmonization is not only neces-

sary between cells of the same scale, but also across

scale bands. Because of the high level of complexity

this harmonization is mostly omitted. Data conflicts

and as such display conflicts are the results when

moving from cell to cell on a “moving map” display

as a ship travels, but it also creates conflicting in-

formation as a navigator is zooming in or zooming

out and with that moves the focus of the ECDIS

from one independently developed scale band to an-

other scale band.

As we can see the chart centric ENC production

process, while it generates a great improvement, it is

almost impossible for the process to generate an in-

creased situational awareness with as little confusion

as possible to the mariner. Even within the responsi-

bility of one single HO. As SOLAS ships have the

tendency to cross borders, the ECDIS systems are

dealing with data sets from different countries. This

increases the complexity and in consequence issues

like overlapping data, data gaps or mismatching of

adjacent cells.

Where “Regional ENC Coordination Centers”

(RENCs) are used, those RENCs are also trying to

help harmonizing the ENCs, but of limited success,

given the complexity of the task.

The current focus on ENC production has a lim-

ited view on coverage within scale bands and on da-

tum code. While this allows concentrated efforts to

produce the necessary country coverage to meet the

timeframe of the IMO ECDIS mandate, future mari-

ners will require a more solid basis of chart data for

their electronic navigation needs. The above dis-

cussed data issues needs to be addressed and re-

solved in order to gain confidence of mariners in

electronic navigation.

The issues I have highlighted are well known and

endless discussions around the globe took place and

are conducted right now trying to find solutions. S-

100, fully developed, will help mitigate some of

those risks. S-100 will move the hydrographic data

collection towards a GIS (Geographical Information

System) oriented data concept, away from cell based

thinking. The future concept will move more and

more data sets from scale dependant data storage

towards the scale independent data concept. In this

concept a natural object, like a buoy or a shallow ar-

ea, will be stored in its real-world location and di-

mensions. The database will contain the object only

once and the rendering engine will compose the dis-

play, based on detail rendering and deconfliction

rules, rather than using an artwork-like cartographic

view.

In a full database centric hydrographic data col-

lection, cell boundaries may still exist, but they are

created to break up the data sets in manageable piec-

es, but will no longer be developed as individually

composed data sets. The hydrographic data will be

manager as a complete set, rather than individual

puzzle pieces, which are stitched together like a

patchwork quilt to create an individual coverage.

This underlying data layer will be rendered based on

situational needs, i.e. zooming level as desired by

the mariner, and as such will result in a situational

centric display.

4 CONCLUSION

The current development of usage of electronic car-

tography in the maritime world has taken a step to-

wards situational awareness and as such has matured

away from simple chart display. This development

will intensify and as such will require in future a

change in how electronic maritime cartography is

developed, composed and stored. The future will fo-

cus on data streams to support data integration and

situational centric rendering.

In addition the financial and organizational pres-

sure on HOs will require optimization of workflows

and better utilization of capacities.

To support these changes a harmonized database

of hydrographic data, a harmonized ENC database is

paramount.

REFERENCES

IMO, 2009, SOLAS (Consolidated Edition)

Jeppesen, 2010, ECDIS – What you need to know

IHO, 2000, IHO Transfer Standard for Digital Hydrographic

Data, Edition 3.1

IHO, 2010, IHO Universal Hydrographic Data Model, Ed 1.0.0

IHO, 2011, www.iho-ohi.net

IHO, 2011, Operational Procedures for the Organization and

Management of the S-100 Geospatial Information Registry,

Ed 1.0.0