GIS IS NOT CARTOGRAPHY

CARTOGRAPHIC BASICS Maps perform two important functions: S Storage medium for information that humanity needs S Provides a picture of the world to help understand spatial patterns, relationships, and environmental complexity Maps tell us: S Where is it? S What is it? S (often) When is it? S What is nearby? How far away? In which direction? How do I get there? S What other things are there also? S How might they be related?

CARTOGRAPHIC BASICS Where am I? After James R. Smith, page 46 How far to my destination? In what direction do I go? How large? What shape?

CARTOGRAPHIC BASICS All maps have the same goal: « Communicating spatial relationships « Communicating the ‘form’ of the landscape Basic characteristics of all maps: « Location « Attribution « Reduction of reality « Scale « Geometrical transformation/projection « Abstractions of reality « Symbolism

CARTOGRAPHIC BASICS Location and Attribution allow many types of relationships to be formed: è Relationships among locations with no attributes – distance, bearing è Relationship among various attributes at the same point è Relationship among different locations of the same attribute è Relationships among locations of combined/derived attributes of given distributions -- spatial distribution of per capita income vs. educational attainment

CARTOGRAPHIC BASICS Classification of maps: ­ Classed by Scale Small scale Medium scale Large scale ­ Classed by Function General reference maps Thematic/special purpose maps Charts ­ Classed by Subject Matter Cadastral maps Plans Soil, vegetation, precipitation, etc. The principal task of cartography is to communicate environmental information. The task of the map designer is to enhance the map user's ability to retrieve information.

CARTOGRAPHIC BASICS Mapping involves information transformations:  Data collection  Selection  Classification  Simplification  Exaggeration  Symbolization  Use of map The cartographer's task - explore the ramifications of each mapping possibility and choose the most appropriate for the intended task. Who is your audience?

Four main cartographic processes:  Collecting and selecting data for mapping  Manipulating and generalizing the data, designing and constructing the map  Reading or viewing the map  Interpreting the information presented on the map Skilled cartographers must be familiar with all mapping activities, including geodesy, surveying, photogrammetry, remote sensing, GIS. Skilled cartographers must be familiar with the principals of human thought and communication. Skilled cartographers must be familiar with the disciplines associated with the environmental features being mapped. CARTOGRAPHIC BASICS

HISTORY OF CARTOGRAPHY Changing ideas about cartography: Earliest maps are figurative, ceremonial, artistic 100 A.D. – the Greeks develop concepts of geometry 1200 A.D. - 'church maps' of the Dark Ages 1300 A.D. - Renaissance brings major expansion of world knowledge, travel 1680 AD – the Enlightenment – concept of 'Western science' and concern with positional accuracy 1800s – place => space; concept of distribution; thematic maps come into being; environmental data becomes important systems approach to the environment => reintegration of themes and concept of cartographic modeling

HISTORY OF CARTOGRAPHY From Robinson, Sixth Edition, page A.D. – geometry 1200 – Dark Ages 1300 – Renaissance 1680 – Enlightenment 1800s – Place => Space Systems Approach

HISTORY OF CARTOGRAPHY Constant goal: Society demands maps that are timely, accurate and complete. There has been a continual demand for greater accessibility to lower cost maps. Cartographers' constant struggle with these demands leads to evolution of maps Changing technology:  Manual techniques are still used today  12 th century – magnetic compass  16 th century – mechanical printing press  17 th century – optical technology  19 th century – photo-chemical technology  1950 – electronic/computer technology The success of computer-assisted mapping rests on the skill of the cartographer and development/ application of computer system components within a cartographic environment.

HISTORY OF CARTOGRAPHY Magnetic Compass Mechanical Printing Press Lens Grinding, Telescope Lenses, Lasers Photography, Lithography Computer Technology

BASIC GEODESY “Geodesy is the science that determines the figure of the earth and the interrelation of selected points on its surface by either direct or indirect techniques.” “Mapping involves determining the geographic locations of features on the earth, transforming these locations into positions on a flat map through the use of map projection, and graphically symbolizing these features.” “Cursed be he who moves his neighbor’s boundary stone.”

BASIC GEODESY The earth is not round:  Authalic sphere – a sphere with the same surface area as the ellipsoid – used as base figure for mapping.  WGS 72 and 84 ellipsoids based on satellite orbital data  Clarke 1866 ellipsoid used for mapping in North America (based on ground measurements made in Europe, India, Peru, Russia, South Africa)  Geoid is a more faithful figure of the earth – 3D shape approximated by mean sea level in the oceans and the surface of a series of sea-level canals crisscrossing the continents.

BASIC GEODESY Cartographic use of sphere, ellipsoid, geoid: Authalic sphere used for small scale maps of countries, continents, larger areas Ellipsoid used for large scale maps such as topographic maps and nautical charts; GPS systems use ellipsoid Geoid used as reference surface for ground surveyed horizontal and vertical positions; elevations determined relative to mean sea level geoid

BASIC GEODESY From James R. Smith, page 34

After James R. Smith, page 52 BASIC GEODESY

Direction on the earth: £ Geographic/true directions determined by the orientation of the graticule on the earths' surface £ Magnetic directions must take into account the compass variation/magnetic declination £ True azimuth – clockwise angle a great circle makes with the meridan at point of origin (changes constantly along the arc) great circles = shortest distance between points £ Constant azimuth – line which makes a fixed angle with all meridians (rhumb line or loxodrome); spirals to pole