Cartography Exam #1
Critiquing a map
audience, purpose, message, LIMITATIONS, current, what is missing what can make it better
John Paul Goode
(Univ. of Chicago) - noted for devising the interrupted homolosine projection, which combines the best qualities of the homolographic (or Mollweide) and sinusoidal projections; it is widely used for maps that portray global distribution. DOESN'T DISTORT CONTINENTS TOO MUCH, DISTORTS OCEANS
The 3 categories of map classification:
scale, function, subject
accurate vs precise
(ACCURACY- close to actual value, measures bias) (precision- measure of SPREAD)
referernce info
(Credits)- legends, scale, credits, supplemental info, compliments map
nominal
(Name of a place no numbers ex Dem or Republican)
design loop
1. Form an idea of the final product 2. Draw on screen (proof plot) 3. Look 4. Edit 5. Rinse/Repeat until happy 6. Make final plot
academic cartography in US
1900-1940 John Paul Goode, Erwin Raisz
hue
a specific tone of color - red, yellow, orange, blue, green, etc. All of these make up the spectrum, commonly seen in a color wheel:
Magenta, Cyan and Yellow
are subtractive primaries-starting with all colors and then taking them away to get the correct, everyday thing, printers cartiridges, start with white and apply pigments to subtract other wavelengths o All of the spectrum is really white, when we take pigments out we get color
Red, Green, Blue
are additive primaries- adding together colors in terms of light, starting with no color and mixng to max one
off map references
back on map, not valuable enough to be on the front of the map
ground
background, spend least time on this, hierarchy, boring
Saturation and brightness
can make the possibilities endless o sat- the colorfulness of a color, grey to vibrant, spectrum is endless o brightness/value- goes from white to black add/sub light
maps purpose
communicate something- map is a holistic piece of information- what is it telling you, cannot remove or hold back info, sometimes have to break carto rules to convey message
circumference eratosthenes
correct circumference within 1000 mi
additive or subtractive
depends on the medium.
neatline
frame of the map
•T in O Maps (orbis terrae, orb or circle of the earth) -
general purpose was to explain the biblical story of the earth- orbit circle of earth, general purpose was to explain biblical story •Jerusalem was portrayed at the center •The three known continents around separated by seas. (Beatine maps) Water outside of Africa Asia and Europe
wooden clock is
harrison chronometer Constructed between 1730 and 1735, H1 is essentially a portable version of Harrison's precision wooden clocks. It is spring-driven and only runs for one day without winding (the wooden clocks run for eight days). The moving parts are controlled and counterbalanced by springs so that, unlike a pendulum clock, H1 is independent of the direction of gravity. Precision wooden clock, springs could control the shifting of seas
metadata
index, we will not see, info is in the attribute table, CPU language, supplemental info doesn't make it on the map
Saturation
is the purity of a color - high saturation means that what you see is going to be rich and full. Low saturation makes the color look dull and grayish
Visual center-
landscape and portrait- 5% of total page height above center, visual layout is top to bottom, L to R
Marcus Agrippa
led the first Roman highway survey (note that Romans were VERY proud of their road system in the empire) e.g. "All roads lead to Rome" - Peutinger Table Portolan Charts
manual technology
production of maps strictly by hand, drawings.
what types of maps fit every type
reference and topos
Ptolemy II Projection:
rounded edges- lat and long - Pseudoconic. "much greater resemblance to the known world in our map." - Curved, parallel circular parallels. Curved meridians, converging at pole- equal area
medium
the message, what the map is represented on- display is part of the symbolization
smaller scale means:
• Fewer features, there is more area and less space • Smoother features -not every bump in the road can be included • Combining features -something's gotta give... • Displacing features -didnt make the cut...
s/l scale
• Large Scale Maps - detailed views of a small region of the earth SMALL AREA • Small Scale Maps - less detailed views of larger regions of the earth, or the entire earth, less detailed for larger regions, generalization, LARGE AREA
subject
• Some also like to group maps by their subjects into classes such as cadasters (land holdings), topographic maps (terrain and relief), etc. These two examples are also comfortable in the general/reference category. • Cadasters (land holdings), topo maps, etc • ARE NOT EXCLUSIVE CATEGORIES
Map functions in GIS
• Storage • Temporary communication (maps only as good as the day they come out) • Intermediate check of data • Final report To be effective, maps must be correctly designed and constructed.
The age of exploration
•1400 - 1900+ was a period of expanding views and knowledge of the earth often led by greed as much as by science. Erickson, Colombus, Mercator
Digital computer mapping and light projection in general
, we use the additive color system - as you add or combine different colors of light into an image, the final product gets closer and closer to white (with white being the final product), which can cover the entire visible spectrum.
Spirit Level
- Allowed easier and more accurate vertical measurements
Dimension
(Point, Line, Area, Volume)
cartography
"When considering design and layout, each map is unique, no rule are absolute for all maps at all times" good cartography is SUDDLE
Eye expects
(1) balance and (2) alignment
Brightness
(intensity) refers to how light or dark a color is. The light bulb analogy works here - if you ramp up a light bulb's current, it gets closer and closer to white (and therefore more intense). As you turn down the current, the light gets less and less intense and eventually goes out. In color science, we are only mixing white or black with our original color to make it more or less bright.
peutinger table
(survey was thought to be based on this type of map). The original chart is on a 22 foot long scroll ( survey based on this kind of map)
Harrison Chronometer
- British Government prize for a sea worthy clock to use in determining positions on earth. Latitude is easy based on the North Star (sextant measurement in Northern Hemisphere), longitude is difficult as you have to know the sun angle at two locations! NEED CONSTANT TIME DISTANCE HELPS LONGITUDE
Map Types: Area Data
- MOST COMMON Choropleth- MOST COMMON (political season), colors/area, generalized Area qualitative- remote sensing, aerial image, takes it and put it into a physical measure Stepped surface- statistical population change, angle is dif, lose shape Hypsometric Dasymetric
Mercator
- a Flemish cartographer who developed a projection for navigation purposes (1569). The Mercator projection allowed compass directions to be read straight from a map for the first time. Draw a straight line for sailing with directions
Optical technology
- affected many of the surveying instruments above: lenses, sights, etc
Sextants
- allowed easier measurement of angles between visible points, horizontal or vertical
Odometer
- allowed quicker measurement of horizontal distances.
portolan charts
- also very adept sailors, the Romans mapped many ports so ships could sail more safely in and out of maritime trading zones.
Electronic technology
- computer technology has revolutionized the process of compiling and producing a map. This is what we will stress throughout the course.
Text: Selection and Placement
- do not cut off labels for points, area put label inside, line go horizontal
Photo-chemical technology
- greatly enhanced reproduction techniques, plate making (later), photos themselves as maps
simultaneous contrast
- how different shades interact with one another, colot patches are effected by the ground- everything interacts
•Columbus
- made the classic error in judgment of the earth's size. •He assumed that because of the great detours created by Africa, that the other way around the sphere would be better to get to China. in judgment of earths size, thought earth was smaller, sail W to china
Mechanical technology
- map reproduction through printing
o Vineland Map-
- rediscovered in 1957- 15th century copy of a 13th cent original, visited in 11 cent too? o Jesuit Father Joseph Fisher- hilter was trying to get artifacts, modified the map to piss of the germans by putting north America on
Map Types: Line Data
- referernce pictures NOT EXCLUSIVE Lines- longer than they are wide, Network- LINEAR, CONNECTIONS TO WIFI, NOT PHYSICAL Flow- origin- show transport/movemnets in terms of volume 1st 1837 mix of a map and a chart, commuting map- map of tangible and intangible things Isoline- isochrome, mapping the cost to drive somewhere Reference
•Leif Erickson
- the Vikings of Northern Europe have been argued to be the first to discover the "new world" (1000) o Vineland map is evidence used in the argument that they beat Columbus to North America- on Newfoundland- island not mainland
Magnetic Technology
- the compass for determining direction on the earth's surface
Ptolemy 3:
-Azimuthal-like -Modified perspective view. -True scale along straight central meridian, tapered scale along Syene parallel (straight), and other lines concave and curved. -Unused or lost.
PTOLEMY's MERIDIANS
-Used 20 minute intervals for lines of longitude. Based on the equinox. Ptolemy's map of the world, about A.D. 150, republished in 1482. Notice the use of latitude and longitude lines and the distinctive projection of this map.
Ptolemy I Projection:
-Used for world map in the first edition (Bologna, 1477). Regional maps used same projection. -Straight converging meridians, converge to north of north pole, conic? -Curved, circular arcs as parallels. (most accurate regions meridians) -Southern hemisphere only partly covered. (big three of Asia, Europe and Africa shows)
PTOLEMY's PARALLELS
-Used length of day variations at 15 minute intervals on longest day (summer solstice). -First parallel at 4 15'N, tenth at 36 N, 21st is Thule.
Eratosthenes
276 - 196 BC. He was the first to try to measure the spherical earth. -A water well in (what is Aswan today) had sun shining on entire water surface at the summer solstice (~6/21) VERY ACCURATE MEASURE 2000 YEARS AGO water well in Egypt Aswan had sun shining on enture water surface (Syene) the summer solstice -Alexandria measurement on same day was 7 degrees 12 minutes off -We don't know which stadia measurement he used, but estimates indicate that he was within 1000 miles of the correct circumference of the earth!
map design
A GIS map is designed in a process called the design loop. Good map design requires that map elements be placed in a balanced arrangement within the neat line.
charts
A special case of the general reference map that takes positional accuracy to an even higher level so they can serve to aid navigation. Routes can be plotted and planned on charts with expectations of extreme accuracy (FAA on a 55 day cycle for aeronautical charts for example) o Positional accuracy info overload, special case of general reference map that takes positional accuracy to an higher level so thy can sere to aid navigation o Routes plotted and planned FAA aeronautical charts
ratio
Absolute zero e.g. dollars, densities, counts, 0=0)
Choosing a Map Type
Cartographers have designed hundreds of map types (methods of cartographic representation). Not all GIS's allow all types. Most have a set of basic types Depends heavily on the dimension of the data to be shown in the map figure. Carto have designed 100s of map types, some good at spatial analysis depends on the dimension of the data
Color and Map Design
Color is a complex visual variable and in a GIS is specified by RGB or HSI values. • Red, Green, Blue are additive primaries • Magenta, Cyan and Yellow are subtractive primaries • Saturation and brightness can make the possibilities endless
compass
Dark ages- The compass becomes more widespread - thought to have come from China around 1200AD, the compass made direction finding much more precise than before. Found that certain rocks move iron fillings Called spoons or landstones
choropleth mapping
Data should be AREA (e.g. States), nominal if political map Data should not suffer from area effect. Boundaries unambiguous- cannot overlap Areas non-overlapping. The Need for Design- should reflect carto knowledge To appear professional and avoid errors, GIS maps should reflect cartographic knowledge about map design. A map has a visual grammar or structure that must be understood and used if the best map design is desired. Visual grammar=hierarchy Cartographic convention (e.g. forests should be green).
Erwin Raisz
Harvard)- mapped physical land forms post WW2
interval
Interval (Arbitrary zero e.g. Sea Level, can compare side by side equator and PM)
Choosing elements
Map research- what you want to use Map compilation Selection Placement Layout- artistic phase Tools in GIS not ideal- other systems are better for adobe
Roman Contributions:
Marcus Agrippa
Map Types: Time
Multiple maps/views in a single frame Animation- movIng map/views in a single frame Ex weather maps, borders chaning, movement of people, landcover change SHOW THE WAY THAT PEOPLE THINK •Moving map •Fly thru •Fly by
medium elements
Page coordinates Ground elements- distinguish figure good map has non, should not compete with the figure itself Graticule/Grid- if need put it on North arrow- not always needed A GOOD MAP IS WHEN YOU CANT TAKE ANYTHING ELSE OUT
Greek contributions
Plato, Aristotle, 4th century BC both these great philosophers promoted the spherical earth as: • Ships would appear to sink into the seas as they neared the horizon, not fall off or just get smaller as they would at a distance • Movement of earth at night provided different stars in view (northern vs southern hemispheres) • Lunar eclipses showed a curved edge on the earths shadow on the moon
figure elements
Point/Line/Area symbols Text- labeling most time consuming, hierarchy Place Names Title- largest and boldest text, most important
Map Types: Point Data- look at pics
Reference- show all kinds of things, everything shown in balance Topographic- bench marks, caves, springs, churches post offices Dot-describe population, infer density, shows distribution no density not about area Picture Symbol- symbols and type of data Graduated Symbol Depends on the scale of the figure.
reference information elements
Scale- not all need scale bar, useful for measuring Projection(s)- how it behaves Sources (2)- cite sources Credits- who made the map, map made for...by... Legend- important, colors, symbols Reliability- who do you blame if something is wrong
ordinal
Small, med., large town, NO TIME, 1st 2nd 3rd cannot compare)
the medium is the ____
The medium is the message • Paper • Film • Mylar • Monitor • Projection • Broadcast TV • THE DISPLAY IS PART OF THE SYMBOLIZATION o Only manual carto that is currently used is cave maps
the dark ages
This period- anti-science, hence the name "dark ages". Teachings of the Church were accepted as science of the day, and European maps from about 1000 - 1450 AD reflected this way of thinking. Post decline Roman empire, no econ discovery- maps went from detailed to simple T in O maps
graphic editor software
Vector- never gets blurry when you zoom in, discrete •Adobe Illustrator •CorelDraw •Freehand Raster- gets pixelated when you zoom in, continuous •Photoshop •CorelPaint •Paint
map
a vague term that is used for a wide variety of physical and theoretical products: they are not real, shrinking the earth and distorting "An image of the environment that has the ability to communicate some element of that environment between two or more persons." e.g. - cartographer and reader graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale."
Ptolemy
made several significant contributions to mapping: -Book "GEOGRAPHY", rejected Eratosthenes' measure and replaced it with one 25% too small as he thought the Canary Islands to Asia was 180 degrees (1/2 of the earth), actually only about 140 degrees -Used seconds to base fraction measurements of distance, introduced MIN AND SECONDS TO BASE FRACTION. -Devised some of the earliest known projections for earth maps on flat paper - (he had 3: Ptolemy 1,2,3)
history of cartography
maps are time capsules MAP ONLY GOOD FOR THE DAY IT IS PUBLISHED Oldest maps were typically rather large scale. (suggests a more limited view of the world perhaps?) not thinking globally -Settlement Plan: may show walls, fields, irrigation ditches, etc. -Roman surveyor sketches
cartographic elements
medium, figure, ground, reference info, border neatline, insets, metadata, off map references
data scaling
nominal, ordinal, interval, ratio
figure
place figure first them move, spend most time on the, most bold, most color
printing, manual cartography, and painting
we use the subtractive color system combining cyan, magenta and yellow causes certain wavelengths to be absorbed or subtracted (when CMY are combined, we get black). Take a look at your color printer cartridge sometime - three colors, when used in certain volumes together absorb light and can similarly create every color for us to see in the visible spectrum.
insets
where are we? Zooms in or out to full scale, •Scale up •Scale down
border
white space between the edge of map and neatline
Map Types: Volume Data
z data connect volume to area [Isoline(again), Stepped Surface, Hypsometric] Gridded fishnet- elevation Realistic perspective- google earth, 3d digitized imagery over 3d model Hill-shaded
examine t in o beatine
• Earliest printed example of a classical T and O map (by Guntherus Ziner, Augsburg, 1472), illustrating the first page of chapter XIV of the Etymologiae. • It shows the continents as domains of the sons of Noah - Sem (Shem), Iafeth (Japheth) and Cham (Ham). • The Hereford Mappa Mundi, about 1300, Hereford Cathedral, England. A classic "T-O" map with Jerusalem at center, east toward the top, Europe the bottom left and Africa on the right. • Reflect the art and thinking at the time- mythical creatures
Age of Technology
•Along with exploration was the need to record the results. Technological advances in many fields aided in measuring positions on the earth for mapping objects. Triangulation - cut down the tedious need for distance measurements by knowing the length of one side and 2 angles in a triangle, we can calculate the other side lengths
Drawn or Cartographic Maps
•Definition is more narrow: a drawn representation, usually on a flat sheet (not to exclude globes however) that has defined relations between itself and the region it depicts.
function
•General or reference maps (charts too) - show WHAT and WHERE things are in the environment as the dominant focus. They stress positional accuracy of all features shown. We refer to them to learn about a new place, build a new building, develop a database, etc. o Reference- for location and learning • Thematic Maps -illustrate the distribution of a particular theme across a study area. They stress the pattern and variation in the theme rather than high positional accuracy.
What is a map and what isn't?
•Space imagery? - 3D into topo •Aerial photography? •Maps on computer screens- arc gis •Spatial computer databases •Globes - some say map others do not because it is not flat, accurate measure •Mental maps
Post WWII -3 big schools/graduate programs
•U. Wisconsin - Arthur Robinson- projections •U. Kansas - George Jenks - jenks natural breaks classification •U. Washington - John Sherman - carto for the blind •Their early programs taught the next generation and cartography grew a great deal across the country.
Visual balance is affected by:
•the "weight" of the symbols- sizing •the visual hierarchy of the symbols and elements (placement) •the location of the elements with respect to each other and the visual center of the map.
