Orienteering map

An orienteering map is a map specially prepared for use in orienteering events. It is a large-scale topographic map with extra markings to help the participant navigate through the course.

These maps are much more detailed than general-purpose topographic maps, and incorporate a standard symbology designed to be useful to anyone, regardless of native language. In addition to indicating the topography of the terrain with contour lines, orienteering maps also show forest density, water features, clearings, trails and roads, earthen banks and rock walls, ditches, wells and pits, fences and power lines, buildings, boulders, and other features of the terrain.

Orienteering maps meant for competition in forested areas are usually 1:15 000 or 1:10 000 scale and 1:4.000 for sprint maps in cities, and parks.

The International Orienteering Federation (IOF) publishes the standard for orienteering maps, including:

• ISOM (International Specification for Orienteering Maps), used for FootO forest maps.
• ISSprOM (International Specification for Sprint Orienteering Maps), used for FootO sprint and TrailO maps.
• ISSkiOM (International Specification for Ski Orienteering Maps), used for SkiO maps.
• ISMTBOM (International Specification for Mountain Bike Orienteering Maps), used for MTBO maps.

Purpose

An orienteering map, along with a compass, helps a person move through an orienteering course of control points quickly. The map must be reliable and accurate so that it can test a person's navigation skills. It shows the land with just the right amount of detail.

Orienteering maps are made by local clubs and are very useful for them. Making these maps can be costly because it takes time, skill, and money for the fieldwork, drawing, and printing. Clubs with more resources, like maps and people, can usually host more events.

Notable examples in the US include Pawtuckaway State Park, New Hampshire and Valles Caldera, New Mexico, which have many rocks and interesting landscapes.

History

In the early days of orienteering, people used regular maps from government agencies. However, these maps were not always updated often enough for orienteering. Over time, special maps were made just for orienteering.

These special maps show more details about the land, like large rocks and new fences, which can help people find their way better. A cartographer named Jan Martin Larsen helped create these special maps.

Map content

Orienteering maps are special maps made for orienteering competitions. The size of the map, called the scale, depends on what kind of event it is. For example, a long-distance foot orienteering event might use a scale of 1:15000. The maps are printed in six main colors, each showing different things like land shapes, rocks, water, plants, and buildings. There is also a special color used to add extra symbols.

Land shapes are shown with lines called contour lines, usually spaced 5 meters apart. Other symbols show small hills, dips, and uneven ground. Rocks and cliffs are shown in black, while water like lakes and rivers are shown in blue. Plants and trees are shown in green or yellow, with white for open areas where you can run easily. Man-made things like roads, fences, and buildings are also shown, with different lines to show if you can pass through them or not.

All orienteering maps must have two special symbols: lines showing magnetic north and register crosses to make sure the colors line up correctly. Other important details like the map’s scale and date may also be included.

Extra symbols in purple or red can be added to show where the start and finish are, as well as points you need to find along the way. These symbols change for each event and are not part of the permanent map.

The rules for making these maps are set by the International Orienteering Federation, and they work for different kinds of orienteering, like mountain bike orienteering and ski orienteering, with a few special symbols for each sport.

Mapping process

The mapping process has four main stages: Creation of the base map, field-work, drawing, and printing.

The base map can be a topographic map made for other purposes, or a photogrammetric plot from an aerial survey. As LIDAR technology improves, base maps with detailed information from LIDAR data are becoming more common. These maps have a lot of information, so careful editing is needed to make them easy to read.

When making maps, special attention is needed for directions. The earth’s surface is curved, so maps use a flat grid that can be slightly off from true north. Orienteering maps are printed using magnetic north, which requires adjustments to the base map.

Field-work involves using a small part of the base map to guide drawing on film with pencils. Modern tools let map-makers use tablets for notes in the field. The map must match the real ground exactly so competitors can find features clearly. If the map and ground don’t match, the feature can’t be used. Maps sometimes need updates, especially in forests where plants grow.

Early orienteering maps were made by correcting existing topographic maps by hand. Hand-drawn maps were created on tracing paper using special tools and materials. Today, computer software like OCAD and OpenOrienteering Mapper helps create digital maps. These tools let maps include courses ready for printing.

Colour maps used to be printed by professional printers in five colours. Now, with better technology, many clubs print their own maps. Using the right paper and size helps make the maps last better.

Map accuracy and map quality

Map accuracy is how useful the map is for someone trying to navigate during a competition. It depends on the work of the person who made the map out in the field. Map quality is about how well the map is drawn and designed. Some countries even hold contests to reward the best map makers, chosen by a special group of judges.