Lexicon

Cadastral map

Cadastral maps show the boundaries of subdivisions of land, often with the bearings and lengths thereof and the areas of individual tracts, for purposes of describing and recording ownership. They may also show culture, drainage, and other features relating to land use and value.

Choropleth map

Thematic map in which areas are colored, shaded, dotted, or hatched to create darker or lighter areas in proportion to the density of distribution of the theme subject.

Contour lines

Imaginary lines on ground, all points of which are at the same elevation above or below a specific datum.

Custom map

Customized maps or tailored maps are cartographic services for a single purpose or a single customer. Traditionally a custom map involved close interaction between a client and a map company, professional map makers or a cartographic publishing companies. Nowadays online services such as Printmaps.net provide convenient access to online custom map editors.

Datum

Datums are reference systems for computing or correlating the results of geographic surveys. There are two types of datums: vertical and horizontal. A vertical datum is a level surface to which heights are being referred. In the United States, the generally adopted vertical datum for levelling operations is the National Geodetic Vertical Datum of 1929. The horizontal datum is used as a reference for position. The North American Datum of 1927 is defined by the latitude and longitude of an initial point (Meade’s Ranch in Kansas), the direction of a line between this point and a specified second point, and two dimensions that define the spheroid. The new North American Datum of 1983 is based on a newly defined spheroid (GRS80); it is an Earth-centered datum having no initial point or initial direction.

Directional map, directions map

Direction maps are used to help visitors and customers find a specific place. They include directions specific to that place, usually by car, public transport or foot.

DPI

DPI stands for “Dots per inch”. It is used to describe the resolution number of dots per inch in a digital print and the printing resolution of a hard copy print dot gain, which is the increase in the size of the halftone dots during printing. Professional printing mainly uses values between 300 dpi and 600 dpi.

Hillshading

Hill shading is a technique for making topography on a map appear three dimensional by the use of graded shadow effects. Generally, the features are shaded as though illuminated from the northwest.

Index map

Index maps are overview maps in smaller scales with reduced contents. They are often used to show the locations of more detailed maps in a larger area.

Legend

The map key or map legend describes how to interpret the map’s symbols and may give details of publication and authorship.

Locator map

Locator maps are typically simple maps used to show the location of a particular geographic area within its larger and presumably more familiar context. Depending on the needs of the cartographer, this type of map can be used on its own or as an inset or addition to a larger map.

Mapbox

Mapbox is a large provider of custom online maps for websites, based in Boston, USA. Mapbox is the creator of, or a significant contributor to some open source mapping libraries and applications, including the MBTiles specification, the TileMill cartography IDE, the Leaflet JavaScript library, and the CartoCSS map styling language and parser.

Meridian

Great circle on the surface of the Earth passing through the geographical poles and any given point on the Earth’s surface. All points on a given meridian have the same longitude.

Photogrammetry

The science of making measurements from photographs, especially for recovering the exact positions of surface points.

Projection

Orderly system of lines on a plane representing a corresponding system of imaginary lines on an adopted terrestrial or celestial datum surface. Also, the mathematical concept for such a system. For maps of the Earth, a projection consists of 1) a graticule of lines representing parallels of latitude and meridians of longitude or 2) a grid.

Route map

Route maps are mainly used in tourism or for outdoor activities. They show city walks, itineraries, cycle routes or hiking trails. Hillshading is useful for route maps in hilly or mountainous areas.

Scale

A scale is the relation between a distance on a map to the real distance in nature. A scale is usually displayed as a relation information such as 1:50,000.

The bigger the number the smalle the scale and the lower the information density on the map.

Signatures

Signatures are symbols or icons for the display of objects or facts in maps. There are point, line and area signatures. The meaning of signatures is listed in the map legend.

Thematic map

Map designed to provide information on a single topic, such as geology, rainfall or population.

Topographic map, topo map

Topo maps present the horizontal and vertical positions of the features represented; distinguished from a planimetric map by the addition of relief in measurable form. Topo maps usually use contour lines and/or hillshading.

Y coordinate

The Y coordinate is part of a cartesic, orthogonal coordinate system and refers to the vertical axis, also called axis of ordinates.

Zoom level

Digital cartography usually uses zoom levels, not scale as in print cartography. In zoom level 0 the whole planet fits within one “map tile”, in zoom level 1 this area is split into four tiles, in zoom level 2 into 16 tiles, and so on.