Everything about Cartographer totally explained
Cartography
or
mapmaking (in
Greek chartis = map and
graphein = write) is the study and practice of making representations of the Earth on a flat surface. Cartography combines science,
aesthetics, and technical ability to create a balanced and readable representation that's capable of communicating information effectively and quickly.
One problem in creating maps is the simple reality that the surface of the Earth, a curved surface in three-dimensional space, must be represented in two dimensions as a flat surface. This necessarily entails some degree of distortion, which can be dealt with by utilizing
projections that minimize distortion in certain areas. Furthermore, the Earth isn't a regular
sphere, but its shape is instead known as a
geoid, which is a highly irregular but exactly knowable and calculable shape.
Maps of all
scales have traditionally been drawn and made by hand, but the recent advent and spread of
computers has revolutionized cartography. Most commercial-quality maps are now made with
software that falls into one of three main types:
CAD,
GIS, and specialized illustration
software.
Functioning as tools, maps communicate spatial
information by making it visible. Spatial information is acquired from
measurement of space and can be stored in a
database, from which it can be extracted for a variety of purposes. Current trends in this field are moving away from analog methods of mapmaking and toward the creation of increasingly dynamic,
interactive maps that can be manipulated digitally.
Cartographic representation involves the use of symbols and lines to illustrate geographic phenomena. This can aid in visualizing space in an abstract and portable format. The cartographic process rests on the premise that the
world is measurable and that we can make reliable representations or models of that reality.
History
The earliest known map to date is a wall painting of the ancient Turkish city of
Çatal Hüyük which has been dated to the late
7th millennium BCE. Other known maps of the ancient world include the
Minoan “House of the Admiral” wall painting from c. 1600 BCE showing a seaside community in an oblique perspective, and an engraved map of the holy
Babylonian city of
Nippur, from the Kassite period (
14th –
12th centuries BCE). The
ancient Greeks and
Romans created maps beginning with
Anaximander in the 6th century BC. In
ancient China, geographical literature spans back to the 5th century BC. The oldest extant Chinese maps come from the
State of Qin, dated back to the 4th century BC during the
Warring States era.
Early forms of cartography in
India included legendary paintings; maps of locations described in Indian
epic poetry, for example the
Ramayana. Indian cartographic traditions also covered the locations of the
Pole star, and other constellations of use.
Mappa mundi is the general term used to describe Medieval European maps of the world. Approximately 1,100 mappae mundi are known to have survived from the Middle Ages. Of these, some 900 are found illustrating manuscripts and the remainder exist as stand-alone documents (Woodward, p. 286).
In the
Age of Exploration from the 15th century to the 17th century, cartographers both copied earlier maps (some of which had been passed down for centuries) and drew their own based on explorers' observations and new
surveying techniques. The invention of the
magnetic compass,
telescope and
sextant enabled increasing accuracy.
Due to the sheer physical difficulties inherent in cartography, map-makers frequently lifted material from earlier works without giving credit to the original cartographer. For example, one of the most famous early maps of North America is unofficially known as the
Beaver Map, published in 1715 by
Herman Moll. This map is an exact reproduction of a 1698 work by
Nicolas de Fer. De Fer in turn had copied images that were first printed in books by
Louis Hennepin, published in 1697, and
François Du Creux, in 1664. By the 1700s, map-makers started to give credit to the original engraver by printing the phrase "After [theoriginal cartographer]" on the work.
Technological changes
In cartography, technology has continually changed in order to meet the demands of new generations of mapmakers and map users. The first maps were manually constructed with brushes and parchment and therefore varied in quality and were limited in distribution. The advent of magnetic devices, such as the
compass and much later
magnetic storage devices, allowed for the creation of far more accurate maps and the ability to store and manipulate them digitally.
Advances in mechanical devices such as the
printing press,
quadrant and
vernier allowed for the mass production of maps and the ability to make accurate reproductions from more accurate data. Optical technology, such as the
telescope,
sextant and other devices that use telescopes, allowed for accurate surveying of land and the ability of mapmakers and navigators to find their
latitude by measuring angles to the
North Star at night or the
sun at noon.
Advances in photochemical technology, such as the
lithographic and
photochemical processes, have allowed for the creation of maps that have fine details, don't distort in shape and resist moisture and wear. This also eliminated the need for engraving which further shortened the time it takes to make and reproduce maps.
In the late 20th century and early 21st century advances in electronic technology led to a new revolution in cartography. Specifically,
computer hardware devices such as computer screens, plotters, printers, scanners (remote and document) and analytic stereo plotters along with visualization, image processing, spatial analysis and database software, have democratized and greatly expanded the making of maps. The ability to superimpose spatially located variables onto existing maps created new uses for maps and new industries to explore and exploit these potentials. See also
digital raster graphic.
Map types
General vs thematic cartography
In understanding basic maps, the field of cartography can be divided into two general categories: general cartography and thematic cartography. General cartography involves those maps that are constructed for a general audience and thus contain a variety of features. General maps exhibit many reference and location systems and often are produced in a series. For example the 1:24,000 scale topographic maps of the
United States Geological Survey (USGS) are a standard as compared to the 1:50,000 scale Canadian maps. The government of the UK produces the classic 1:63,360 (1 inch to 1 mile) "Ordnance Survey" maps of the entire UK and with a range of correlated larger- and smaller-scale maps of great detail.
Thematic cartography involves maps of specific geographic themes oriented toward specific audiences. A couple of examples might be a
dot map showing corn production in Indiana or a shaded area map of Ohio counties divided into numerical
choropleth classes. As the volume of geographic data has exploded over the last century, thematic cartography has become increasingly useful and necessary to interpret spatial, cultural and social data.
An
orienteering map combines both general and thematic cartography, designed for a very specific user community. The most prominent thematic element is shading that indicates degrees of difficulty of travel due to vegetation. The vegetation itself isn't identified, merely classified by the difficulty ("fight") that it presents.
Topographic vs topological
A
topographic map is primarily concerned with the
topographic description of a place, including (especially in the 20th century) the use of
contour lines showing elevation.
Terrain or relief can be shown in a variety of ways (see
Cartographic relief depiction).
A
topological map is a very general type of map, the kind you might sketch on a napkin. It often disregards scale and detail in the interest of clarity of communicating specific route or relational information.
Map design
Arthur H. Robinson, an American cartographer influential in thematic cartography, stated that a map not properly designed "will be a cartographic failure." He also claimed, when considering all aspects of cartography, that "map design is perhaps the most complex." Robinson codified the mapmaker's understanding that a map must be designed foremost with consideration to the audience and its needs.
From the very beginning of mapmaking, maps "have been made for some particular purpose or set of purposes". The intent of the map should be illustrated in a manner in which the percipient acknowledges its purpose in a timely fashion. The term
percipient refers to the person receiving information and was coined by Robinson. The principle of
figure-ground refers to this notion of engaging the user by presenting a clear presentation, leaving no confusion concerning the purpose of the map. This will enhance the user’s experience and keep his attention. If the user is unable to identify what is being demonstrated in a reasonable fashion, the map may be regarded as useless.
Making a meaningful map is the ultimate goal. MacEachren explains that a well designed map "is convincing because it implies authenticity" (1994, pp. 9). An interesting map will no doubt engage a reader. Information richness or a map that's multivariate shows relationships within the map. Showing several variables allows comparison, which adds to the meaningfulness of the map. This also generates hypothesis and stimulates ideas and perhaps further research. In order to convey the message of the map, the creator must design it in a manner which will aid the reader in the overall understanding of its purpose. The title of a map may provide the "needed link" necessary for communicating that message, but the overall design of the map fosters the manner in which the reader interprets it (Monmonier, 1993, pp. 93).
In the 21st century it's possible to find a map of virtually anything from the inner workings of the
human body to the
virtual worlds of
cyberspace. Therefore there are now a huge variety of different styles and types of map - for example, one area which has evolved a specific and recognisable variation are those used by
transit organisations to guide
passengers, namely
Urban rail and metro maps, many of which are loosely based on 45 degree angles as originally perfected by
Harry Beck and
George Dow.
Naming conventions
Most maps use text to
label places and for such things as a map title, legend, and other information. Maps are often made in specific languages, though names of places often differ between languages. So a map made in English may use the name
Germany for that country, while a German map would use
Deutschland, and French map
Allemagne. A word that describes a place using a non-native terminology or language is referred to as an
exonym.
In some cases the proper name isn't clear. For example, the nation of Burma officially changed its name to
Myanmar, but many nations don't recognize the ruling junta and continue to use
Burma. Sometimes an official name change is resisted in other languages and the older name may remain in common use. Examples include the use of
Saigon for
Ho Chi Minh City,
Bangkok for
Krung Thep, and
Ivory Coast for
Côte d'Ivoire.
Difficulties arise when
transliteration or
transcription between
writing systems is required. National names tend to have well established names in other languages and writing systems, such as
Russia for Росси́я, but for many placenames a system of transliteration or transcription is required. In transliteration the symbols of one language are represented by symbols in another. For example, the
Cyrillic letter
Р is traditionally written as
R in the
Latin alphabet. Systems exist for transliteration of
Arabic, but the results may vary. For example, the Yemeni city of
Mocha is written variously in English as Mocha, Al Mukha, al-Mukhā, Mocca, and Moka. Transliteration systems are based on relating written symbols to one another, while transcription is the attempt to spell in one language the phonetic sounds of another. Chinese writing is transformed into the Latin alphabet through the
Pinyin phonetic transcription systems. Other systems were used in the past, such as
Wade-Giles, resulting in the city being spelled
Beijing on newer English maps and
Peking on older ones.
Further difficulties arise when countries, especially former colonies, don't have a strong national geographic naming standard. In such cases cartographers may have to choose between various phonetic spellings of local names versus older imposed, sometimes resented, colonial names. Some counties have multiple official languages, resulting in multiple official placenames. For example, the capital of Belgium is both
Brussel and
Bruxelles. In Canada, English and French are official languages and places have names in both languages.
British Columbia is also officially named
la Colombie-Britannique. English maps rarely show the French names outside Quebec, which itself is spelled
Québec in French.
The study of placenames is called
toponymy, while that of the origin and historical usage of placenames as words is
etymology.
Map symbology
The quality of a map’s design affects its reader’s ability to extract information, and
to learn from the map. Cartographic
symbology has been developed in an effort to portray the world accurately and effectively convey information to the map reader. A legend explains the pictorial language of the map known as its symbology. The title indicates the region the map portrays; the map image portrays the region and so on. Although every map element serves some purpose, convention only dictates inclusion of some elements while others are considered optional. A menu of map elements includes the neatline (border),
compass rose or north arrow, overview map, scale bar,
projection, and information about the map sources, accuracy and publication.
When examining a landscape, scale can be intuited from trees, houses and cars. Not so with a map. Even such a simple thing as a north arrow is crucial. It may seem obvious that the top of a map should point north but this might not be the case.
Color likewise is equally important. How the cartographer displays the data in different hues can greatly affect the understanding or feel of the map. Different intensities of hue portray different objectives the cartographer is attempting to get across to the audience. Today, personal computers can display up to 16 million distinct colors at a time even though the human eye can distinguish only a minimum number of these (Jeer, 1997). This fact allows for a multitude of color options for even for the most demanding maps. Moreover, computers can easily hatch patterns in colors to give even more options. This is very beneficial when symbolizing data in categories such as quintile and equal interval classifications.
Quantitative symbols give a visual measure of the relative size/importance/number that a symbol represents and to symbolize this data on a map there are two major classes of symbols used for portraying quantitative properties: Proportional symbols change their visual weight according to a quantitative property. These are appropriate for extensive statistics.
Choropleth maps portray data collection areas (such as counties, or census tracts) with color. Using color this way, the darkness and intensity (or value) of the color is evaluated by the eye as a measure of intensity or concentration (Harvard Graduate School of Design, 2005).
Map generalization
A good map has to provide a compromise between portraying the items of interest (or
themes) in the
right place for the map
scale used, against the need to annotate that item with text or a symbol, which takes up space on the map medium and very likely will cause some other item of interest to be displaced. The cartographer is thus constantly making judgements about what to include, what to leave out and what to show in a
slightly incorrect place - because of the demands of the annotation. This issue assumes more importance as the scale of the map gets smaller (i.e the map shows a larger area), because relatively, the annotation on the map, takes up more space
on the ground. A good example from the late 1980's was the
Ordnance Survey's first digital maps, where the
absolute positions of major roads shown at scales of 1:1250 and 1:2500 were sometimes a scale distance of hundreds of metres away from
ground truth, when shown on digital maps at scales of 1:250000 and 1:625000, because of the overriding need to annotate the features.
In popular culture
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