SHOM Raster GeoTIFF Marine Charts – Arctic Ocean

Introduction

SHOM raster GeoTIFF marine charts of the Arctic Ocean are georeferenced digital charts designed for the preparation, analysis and visualization of Arctic maritime areas in a compatible computer environment. They allow the cartographic information represented on a raster marine chart to be used digitally, while retaining its geographical position through the georeferencing data contained in the GeoTIFF file.

The Arctic Ocean is a particularly complex navigation area. Low temperatures, seasonal or permanent sea ice, icebergs, changing weather conditions, limited port infrastructure and the remoteness of inhabited areas make thorough navigation planning especially important.

A SHOM digital raster GeoTIFF marine chart is therefore a tool for studying an area, preparing a route and integrating marine cartography into compatible navigation software. It can be relevant to sailors, maritime professionals, polar expeditions, scientific vessels and users of digital charting software.

What is a SHOM raster GeoTIFF marine chart?

A raster marine chart is a digital representation of a nautical chart in the form of a georeferenced image. Unlike vector cartography, which stores individual geographical objects as separate data, raster cartography reproduces the graphical appearance of the chart.

Depending on the chart reference concerned, it may include:

• soundings and depths;

• bathymetric contours;

• coastlines;

• shoals;

• rocks and hazards;

• wrecks where charted;

• navigation aids;

• lights and buoys;

• hydrographic information;

• specific limits or indications shown on the chart.

The GeoTIFF format adds information to the image that allows it to be geographically positioned. The file can therefore be used by software capable of reading and interpreting this type of georeferenced data.

It is important to distinguish a standard TIFF file from a genuine GeoTIFF file: a simple image does not necessarily contain the information required to position it within a navigation system.

Why use a SHOM digital marine chart in the Arctic Ocean?

Navigation in the Arctic Ocean requires particularly rigorous chart preparation. Distances are considerable, shelter can be limited and navigation conditions can change rapidly.

A SHOM raster GeoTIFF marine chart can be used to:

• prepare navigation in Arctic regions;

• study a maritime route before an expedition;

• analyse approaches to a coastal area;

• prepare navigation around Arctic archipelagos;

• study charted depths and hazards;

• integrate digital cartography into compatible software;

• prepare a route near polar regions.

Digital cartography makes preparatory work on land easier. It allows different route options to be studied before departure and provides a geographical representation adapted to the computer environment being used.

Geographical coverage of the Arctic Ocean

The Arctic Ocean extends around the North Pole and connects with the Atlantic and Pacific Oceans. It includes vast maritime areas bordered by the coasts of northern Europe, Russia, Alaska, Canada and Greenland.

The exact coverage of a SHOM GeoTIFF marine chart nevertheless depends on the chart reference concerned. It is therefore essential to check the geographical area covered by each file before using it to plan a voyage.

Depending on the area being studied, Arctic cartography may concern:

• approaches to Greenland;

• areas around Iceland and the northern seas;

• Arctic archipelagos;

• approaches to the Barents Sea;

• certain areas of the Northeast Passage;

• Canadian Arctic regions;

• approaches to Alaska and the Bering Strait.

A chart covering a very large area does not necessarily provide sufficient detail for coastal navigation or port approaches. Choosing the correct chart reference and scale is therefore essential.

Arctic navigation and sea ice

The presence of ice is one of the main characteristics of navigation in the Arctic Ocean.

A marine chart provides hydrographic and geographical information, but it should not be regarded as a real-time representation of sea ice or iceberg positions.

Arctic navigation planning must therefore take into account additional information concerning:

• sea-ice extent;

• ice concentration;

• ice movement;

• icebergs;

• weather forecasts;

• winds;

• temperature;

• visibility;

• sea conditions.

Charting and operational ice information are therefore complementary. A GeoTIFF chart does not replace the up-to-date data required for polar navigation.

Example: preparing navigation in Greenland

Consider a sailing yacht or expedition vessel preparing a voyage in Greenland.

The first step is to study the general area in order to identify the main navigation sectors and possible routes. Digital cartography can then be used to progressively examine coastal areas.

The navigator can study:

1. the departure area;

2. the general route towards Greenland;

3. coastal approaches;

4. charted fjords and passages;

5. anchorage or shelter areas where represented;

6. the destination area.

As the vessel approaches the coast, scale becomes particularly important. A general chart used to prepare a crossing does not necessarily provide the level of detail required for navigation inside a fjord or through a confined area.

Raster GeoTIFF and vector cartography

The difference between raster and vector charts is important for understanding how digital chart data works.

A raster GeoTIFF chart is a georeferenced image. It retains the graphical appearance of the chart, including symbols, colours, text, soundings and depth contours.

A vector chart, by contrast, consists of individual geographical objects. The software can then interpret a depth, coastline, navigation mark or area separately.

The two technologies meet different requirements. Raster has the particular advantage of preserving a representation very close to traditional marine cartography.

The choice depends on the software being used, the type of navigation planned and the available data.

Using the chart with navigation software

A SHOM GeoTIFF marine chart is not automatically compatible with all navigation or charting software.

Software such as Adrena or ScanNav can use certain georeferenced raster data, but exact compatibility depends on the file being used and the software version.

Before using a SHOM digital raster GeoTIFF marine chart, it is recommended to check:

• the exact chart reference;

• geographical coverage;

• scale;

• resolution;

• coordinate reference system;

• map projection;

• file format;

• software compatibility;

• licensing and terms of use;

• any applicable update conditions.

The GeoTIFF format alone therefore does not guarantee compatibility with a particular software application.

Preparing navigation in the Arctic Ocean

Preparing an Arctic voyage requires several sources of information to be cross-referenced.

Digital marine cartography makes it possible to study the geography and hydrography of an area, but it must be supplemented by the information required for actual navigation.

Particular attention should be paid to:

• charted depths and hazards;

• coastal approaches;

• possible routes;

• ice areas;

• weather forecasts;

• winds and currents;

• swell;

• up-to-date nautical information;

• any navigation restrictions;

• available shelter and infrastructure.

For a polar expedition, navigation redundancy and the availability of offline chart data are also important aspects of preparation.

How to choose a SHOM GeoTIFF marine chart for the Arctic Ocean?

Before selecting a raster GeoTIFF marine chart of the Arctic Ocean, several criteria should be checked.

Geographical area

The first question concerns the actual coverage of the chart. A reference may cover a very large region without necessarily including the specific area required at the desired level of detail.

Scale

The scale must be appropriate for the intended use. A general chart may be suitable for planning a long-distance route, while coastal navigation generally requires more detailed cartography.

Software

Compatibility with the navigation software should be checked before use. The fact that a file is in GeoTIFF format does not mean that it will be recognized by every system.

Coordinate reference system

The georeferencing information and projection must be compatible with the charting environment being used.

Additional information

In the Arctic, cartography must be combined with weather data, ice information and current nautical information.

Conclusion

SHOM raster GeoTIFF marine charts of the Arctic Ocean provide a georeferenced digital charting solution for preparing and analysing navigation in polar regions.

The raster format preserves a graphical representation close to that of a traditional marine chart, while GeoTIFF georeferencing allows it to be accurately positioned within compatible software.

In the Arctic Ocean, however, charting must form part of an overall navigation plan. The presence of sea ice, icebergs, weather conditions, currents and the remoteness of infrastructure make complementary operational information essential.

Choosing the correct SHOM chart reference, geographical coverage and scale is therefore critical. A general chart intended to prepare an Arctic route does not necessarily replace sufficiently detailed cartography for a coastal approach, fjord or confined navigation area.

FAQ – SHOM Raster GeoTIFF Marine Charts of the Arctic Ocean

What is a SHOM raster GeoTIFF marine chart of the Arctic Ocean?

It is a georeferenced digital marine chart representing SHOM cartography in raster format for a specific geographical area of the Arctic Ocean. The GeoTIFF format combines the chart image with the information required for geographical positioning.

What is a SHOM digital GeoTIFF marine chart used for in the Arctic?

It can be used to prepare polar navigation, study a maritime route, analyse a coastal area or integrate raster cartography into compatible software.

Does a SHOM GeoTIFF chart cover the entire Arctic Ocean?

No. Coverage depends on the chart reference concerned. The exact area covered by the file should therefore be checked before planning a voyage.

Does a GeoTIFF chart show the position of icebergs?

No. A marine chart represents the hydrographic and geographical information associated with its reference. The position and movement of icebergs require up-to-date operational information.

Is a SHOM GeoTIFF chart sufficient for navigation in the Arctic?

No. It is one element of chart preparation and should be supplemented by weather information, ice data, current nautical information and other information required for navigation.

Can a SHOM GeoTIFF chart be used with Adrena?

Adrena can use certain georeferenced raster data. Compatibility should nevertheless be checked for the SHOM reference, GeoTIFF file and software version concerned.

Is a SHOM GeoTIFF chart compatible with ScanNav?

ScanNav can use certain georeferenced raster data. The exact compatibility of the file and software version being used should be checked.

What scale should be used for navigation in the Arctic Ocean?

The scale depends on the intended use. A general chart may be suitable for planning a long-distance route, while more detailed cartography is required for coastal approaches, fjords and confined passages.

What is the difference between a raster GeoTIFF chart and a vector chart?

A raster GeoTIFF chart is a georeferenced image reproducing the graphical representation of a marine chart. A vector chart consists of separate digital geographical objects that the software can interpret individually.

Why should the SHOM chart reference be checked before using a GeoTIFF chart?

Because each reference has its own geographical coverage, scale and level of detail. A chart suitable for general route planning is not necessarily suitable for coastal navigation.

Can a SHOM GeoTIFF chart be used to prepare navigation in Greenland?

Yes, provided that the chart reference covers the relevant area and the file is compatible with the software being used. For coastal approaches and navigation inside fjords, appropriate charting at the required scale and level of detail is necessary.