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GIS
Exam 1
97
Geography
Undergraduate 4
10/02/2013

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Term
What type of data makes GIS unique?
Definition
Spatial
Term
3 Types of vector data
Definition
Point
Line
Polygon
Term
What number system do computers use?
Definition
Binary
Term
Each state (0 or 1) is called?
Definition
A bit
Term
Fundamental data unit in digital computers
Definition
Byte
Term
How many bits are in a byte?
Definition
8
Term
How many unique values can be in a byte
Definition
256
Term
What does this equal
10111
Definition
43
Term
BLOB
Definition
Binary Large Object
Term
Discrete (5)
Definition
Do not exist between observation points
Form a separate entity
Ex: zebras and lakes
Can only exist as whole objects
Represented as a vector
Term
Continuous (4)
Definition
Exist spatially between objects
Fractional parts are allowed
Ex: Elevation, Precipitation
Represented as a raster
Term
Geographical Phenomena
Definition
Voting Patterns
Climate
Glaciers
Migration
Term
Geographical Data
Definition
Usually numerical information to describe or measure geographical phenoma
Term
Nominal Scales (4)
Definition
Simplest level of measurement scale
Objects classed into groups
Cannot perform math between classes
Can only determine equality or inequality
Term
Ordinal Scale (2)
Definition
Scaling based on a hierarchy
No means to determine how much distance separates observations
Term
Interval Scaling (4)
Definition
Can array events in order of rank
Know distance between observations
Units of interval scale equal throughout
The chosen intervals may not have natural origins, and does not make sense to make ratios between numbers
Term
Ratio Scaling
Definition
Ordering events with known distances separating the events
Ratio-scaling magnitudes are absolute and have a known starting point
The scale of measurement has a 0 as its origin
Most measurement in physical sciences is done one ration sclaes
Term
Nominal Scale Examples
Definition
Democrat
Republican
Independent
Term
Ordinal Scale Examples
Definition
Class ranking (without knowing GPA)
Finishing position of racers
Mohs Hardness Scale
Likert Scale
Term
Interval Scaling Example
Definition
Fahrenheit Temperature Scale
Celsius Temperature Scale
SAT Score
Term
Ratio Scaling Example
Definition
Kelvin Temperature Scale
Elevation above sea level
Term
Dimensions of Area
Definition
2-D
Term
Dimension of Line
Definition
1-D
Term
Dimension of Point
Definition
0-D
Term
Natural Areal Units
Definition
Lakes
Farms
Cities
Forests
Term
Artificial Areal
Definition
Imposed by researchers
An attempt to organize reality or to facilitate data collection
-Regions
-Census Tracts
Term
What characteristics of phenomena might make them hard to represent in GIS (4)
Definition
Ill defined spatial extent
Ill defined boundaries
Entities that change over time
Regions easy to characterize?
Term
Aggregate Areal Units
Definition
Composed of two or more singular units
Term
Who coined the term GIS?
Definition
Roger Tomlinson
Term
Where did Roger Tomlinson work?
Definition
Canadian Department Forestry and Rural Development
Term
When was GIS created?
Definition
Early 1960s
Term
What was the first true GIS
Definition
The Canadian Geographic Information System (CGIS) created in 1966
Term
GIS must be composed of these 3 things
Definition
A Database containing attribute information
Spatial or Map Information
A way to link the first two
Term
GIS can do the following with spatial information (6)
Definition
Capture
Archive
Retrieval
Projection
Analysis
Display
Term
GIS queries are:
Definition
ad hoc or context specific
Term
Who coined the term GIS
Definition
Michael Goodchild
Term
Three bases for classifying Geograpahic Problems
Definition
The scale or level of geographic detail
The basis of their intent or purpose
Timescale of the problem
Term
Geospatial
Definition
Implying a subset of the spatial applied specifically to the Earth's surface and near surface
Term
Large map scales have what size denotation?
Definition
Small
Term
What type of scale remains true if map is enlarged or reduced
Definition
Graphical scale
Term
When we measure a position on Earth what type of coordinates are used?
Definition
Spherical coordinates
Term
Geocentric Latitude
Definition
The angle between the equatorial plane and a line from the local position to the intersection of the axis of rotation with the equatorial plane. Determination based on a spherical earth is also termed Authalic latitude
Term
Geodetic Latitude
Definition
The angle between the plane of the geodetic equator and the local direction of the geodetic vertical. Geodetic Latitude and Geographic Latitude are practically the same
Term
Geographic Latitude
Definition
Obtained by surface observation of angular altitude of the visible pole. Due to flattening of the geoellipsoid, local plumb variates from geocentric in relation to distance from the equator and poles, and length of a geofractional meridional line will vary in length by latitude, increasing towards the pole. At any particular latitude, the geographic and geodetic latitude values are greater than the equivalent geocentric latitude. Geographic latitude is also termed Astronimical Latitude
Term
What coordinate system does GIS work in?
Definition
Rectangular coordinate systems (X,Y)
Term
In ArcGIS rectangular coordinate system is known as:
Definition
Geographic Coordinate System (GCS)
Term
What is degrees, minute, second converted to for computers
Definition
Decimal degrees
Term
Decimal Degree=
Definition
degree+(minute+[second/60])/60
Term
4 coordinates areas of the world
Definition
+- ++

-- -+
Term
Map Design Process
Definition
Problem Identification
Preliminary Ideas
Design Refinement
Analyze
Implementation
Term
Elements found on most thematic maps (9)
Definition
Title
Legend
Scale
Credits
Mapped Areas
Graticule
Border (neatline)
Symbols
Place Names
Term
What are the two factors that affect visual balance
Definition
Weight
Direction
Term
Choropleth
Definition
The mapping of values by place, or more precisely...mapping values by enumeration unites
Term
Choros means:
Definition
Place
Term
Pleth means:
Definition
Value
Term
What is an enumeration unit?
Definition
Statistical or political units by which the data is gathered
Term
When to use Choropleth Map
Definition
When data occurs in well defined enumeration units
If data can be expressed as ratios or proportions
Should NOT be used if exact or precise data values within enumeration units must be shown
Term
What kind of data should a Choropleth map use?
Definition
Discrete Data
Term
Kinds of Discrete Data
Definition
Totals
Derived Values
Term
Totals:
Definition
Generally should not be used as different sized enumeration units distort the data presentation
Term
Derived Values:
Definition
Ratios or densities
Term
Pattern Uniqueness
Definition
Different Patterns
Different Textures
Different Orientation
Term
What in the boundary between a tone and a pattern?
Definition
75 lines per inch
Term
The Dot Map (3)
Definition
Mapping of discrete geographical phenomena
Technique has been used for more than a hundred years
While any symbol can be used, the dot has become the most commonly used symbol and hence the term dot map
Term
Disadvantage of dot maps
Definition
Map interpretation may be difficult
Method is time-consuming
Frequently map design prevents the recovery of the original data
Term
The larger a circle is for a proportional map the:
Definition
Greater the under estimationn
Term
Continuos Circle
Definition
Means that every different values on the map is represented by a different sized circle
Term
Range-graded Circles
Definition
Means that the data is divided into classes and each class is represented by one size circle
Term
Isarithmic Map
Definition
A planimetric graphic representation of a three-dimensional volume
Can be "fishnet", shaded relief, isolines, or raised statistical area
Term
Isoline Map
Definition
A system of quantitative line symbols that attempt to portray the undulating surface of a three-dimensional volume
Each line represents a single value, ie, all points on that line have the same value
Term
Flow Maps (4)
Definition
Flow maps show the linear movement between places
Flow maps are sometimes referred to as dynamic maps
They can be qualitative or quantitative
In most instances the cartographer attempts to depict the actual route taken, but this must be balances with the need for generalization in maps
Term
Quantitative Flow Map
Definition
Lines are scaled so that they are proportional to the amounts they represent
Term
KISS
Definition
All information should be kept simple, including flow line scaling
Term
When using interposition:
Definition
The smaller lines go on top of the larger ones
Term
Non-contiguous cartograms
Definition
Preserves the shape of each enumeration unit
Empty space between the enumeration units
Enumeration units will not fit together to maintain the contiguous character of the map
Term
What is correlation to the data and area of the enumerations units
Definition
Reverse correlation
Term
Requirements for selecting a cartogram
Definition
The reader must be familiar with the overall shape of the study area
Must also be familiar with the shape of the individual enumeration units that comprise the study areas
Term
First description of the Earth as a Sphere
Definition
Appears in Plato's Phaedo
Term
First person to say Earth revolved around the sun
Definition
Aristarchus
-Greek astronamer
Term
Who first said Earth was not a perfect sphere
Definition
Issac Newton and Huygen said it was an oblate spheroid based on gravity
Picard and Cassini said it was prolate
Term
Who first calculated Earth's circumference
Definition
Eratosthenes
Term
Geoid
Definition
Earth-Shaped
Earth's mean-sea-level surface
For land he geoid would be the height to which water would rise in a transcontinental canal
Term
Geoid is represented by:
Definition
Equipotential Surface
-defined by the amount of work required to move a unit mass from one surface to another these perpendicular distance between the surfaces varies over the earth
Term
What model do we use in GIS?
Definition
Ellipsoid or spheroid
Term
Some elements of a geodetic datum
Definition
semi-major axis of the ellipsoid
semi-minor axis of the ellipsoid
latitude of the initial point
longitude of the initial point
azimuth from the initial point to another point
assumes ellipsoid and geoid are coincident at initial point and earth's spin is parallel to ellipsoids minor axis
Term
NAD27 Orgin
Definition
Meade's Ranch, Kansas
Clarke Spheroid of 1866
Term
Datum
Definition
A reference point or surface against which position measurements are made, and an associated model of the shape of the earth for computing positions
Term
Geodetic datum
Definition
A mathematical model of the earth upon which geodetic computations are based
Term
Datum is set at:
Definition
Earth's center of mass
Term
Global datums have to take into account
Definition
earth's gravitational attraction and centrifugal acceleration
Term
Map Projection Process
Definition
Geoid
Reference Ellipsoid
Perfect Sphere
Map Projection
Term
Four General Classes of Maps
Definition
Equal Area
Conformal
Equidistant
Azimuthal
Term
Conformal
Definition
Shape is preserved
Lines of longitude and latitude cross at right-angles
Term
Three families of projections
Definition
Azimuthal=plane
Cylindrical=cylinder
Conic=cone
Term
Equidistant
Definition
Distances along designated great circles are true or
distances from one point to all others is true
Term
Azimuthal
Definition
True direction is shown from one central point to all other points
Term
Secant
Definition
Plane intersects globe
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