69 Cards in this Set
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How does GIS differ from data base management?
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it has geographic entities and operators
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What is an example of a geographic entity and attribute?
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Entity: building
Attribute: height
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Whats an example of a geographic operator?
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area computation
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Name at least three methods to put breaks in a classification scheme:
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Standard deviation, natural breaks, equal intervals, quartile
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Spatial layers: if i have 17 spatial layers, all with a spatial resolution and accuracy of 10 meters, and I have one more layer than the streams in it and its only good to a 100 meters a km, what is the value of the final analysis? how good can it be?
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10 meters, my analysis is only as good as the WORST layer I have
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What is a geodetic datum?
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defines the SIZE and SHAPE of the earth and the ORIGIN and ORIENTATION of a coordinate system
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If you were choosing a projection for vermont, which would you choose?
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transverse mercator (regional shapes with longer north-south dimension)
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If you were choosing a projection for tennessee which would you choose?
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Lambert conformal conic (for regional shapes with longer east-west dimension)
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What is the appropriate projection for a global display?
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Robinson
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How accurate are a bunch of points derived from a lot of addresses?
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minimum of 100 meters
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Theodolite -- what is the zero in the z direction?
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local level
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Theodolite -- what is the zero for the horizontal level? (for the x value)
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an arbitrary base line, an arbitrary zero
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Map scale is equivalent to...
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database resolution
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Which term is closer to mapscale or database resolution: precision or accuracy?
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precision
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True north
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The point where all longitude lines converge.
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Grid north
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The north on the gridded map indicated by a north arrow that follows horizontal lines
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Magnetic North
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The north a compass points to. unreliable because it changes over time
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How many satellites do you need for a complete measurement?
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4
(x,y,z,atomic time)
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Points in arc/info are known as...
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nodes
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Areas in arc/info are known as....
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polygons
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Points in arc/info are known as....
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Arcs
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How does arc/info know the direction of an arc?
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the "from" node
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What is the difference between vector (object) and field (raster) representation of space?
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A raster (area) is continuous, a vector is confined (points, lines, surfaces)
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Why do you flatten the earth?
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Its better for analysis, you can selet which distortions to minimize (distance, direction, scale, area)
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How is the prime meridian defined?
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It depends on the geodetic datum, because they all have different locations of the prime meridian. There is no definite answer, it depends on which coordinate system to use.
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What is cohens kappa?
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A measure of how much the database differs from reality
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What is MCE (multiple criteria evaluation)?
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Factors, weights, qualitative
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What is scale?
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it shows accuracy
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How small is the smallest point that can be placed on a map?
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.5 mm / 0.02 in
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Is it possible to have two data points in a polygon?
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no
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Which map projection best preserves local shapes?
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Transverse mercator
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Where is the prime meridian?
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Anywhere you want it to be. It depends on what geodetic datum you chose.
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Remote sensing satellite systems can portray a healthy vegetation index by using ....
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in red/green and infrared
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What would be the symbol for a building that would look much like a building?
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A pictograph
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PPGIS
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Public Participation in GIS
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Name some approaches to GIS:
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co-learning, cooperation, compliance, collective action
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Whats the difference between land use and land cover?
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Land cover -- features on the earth measured by remote sensing land use -- human use, the way we define it
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Whats an example of a chloropleth map?
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census tracts, the boundaries of the zones are established independently of the data
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Chloropleth map
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the boundaries of the zones are established independently of the data --- strictly defined and cannot be changed
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dasymetric map
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Comes from different measurements, do not follow pre determined boundaries
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Whats an example of a dasymetric map?
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soil map
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What is an example of an isopleth map?
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Temperature map
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Isopleth map
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Map comprised of lines (isolines) of equal attribute value
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Why did people start using infrared imagery?
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To detect green things
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What is the potentional of a map that has a 1: 1,200,000 ??
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1. Divide (1,200,000/1000)
2. Divide (1200/2)
3. answer = 600
the precision is 600 meters
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Krieging
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GIS analysis use it for interpolation. They use it for guessing. Based on autocorrelation and distances weighted interpolation
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What projection to you use if you want to compute the area of something:
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equal area conformal conic
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WGS84 World Geodesic System of 1984
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widely accepted, globally current global reference system
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Qualitative VS Quantitative
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Qualitative (large, medium, small)
Quantitative (1,2,3,4)
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What two important features does GIS add to relational database management systems?
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geographic entities and operators
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How is a geographic entity captured as geospatial data?
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As either a vector (object) or raster (field)
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What is a geographic entity best described as an object?
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Vector -- points
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What is an example of a geographic entity best described as a field?
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Raster (area)
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Under what circumstances might a city be described as a point?
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When the city itself is not the focus of investigation, never as a reference point on a map
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What are two examples of the difficultly in defining a "lake"?
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Manmade lake or natural lake? how small can a lake be and how big can a pond be?
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Why is the notion of a "coastline" a problem when defining geographic representations?
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Defaults on scale and accuracy, how much of a coastline?
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What is an example of a ratio measurement?
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area
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What is an example of a cyclic measurement?
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azimuth
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What measurement type is a FIPS code for a state?
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nominal
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What was the original definition of a meter?
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1:10,000,000 of the distance from the equator to the north pole
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What are three examples of descriptive statistics?
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Average, median, mean
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What is the important characteristic of a conformal projection?
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It maintains relative shape
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What is magnetic north a problem for describing directions on the earth?
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it changes over time
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The detect features on the ground, you must sample..
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At intervals half the distance of the size of the features
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The actual gravity shape of the earth is...
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A complex field that changes everywhere
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What is the most important function of a GIS process?
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data analysis
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ESRI stands for
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EnvironmentalSystems Research Institute
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True or false: Network analysis is a GIS analysis function
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TRUE
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Meridians are lines of ______ that measure in the ________ direction
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longitude, EAST-WEST
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