exammistrerm Flashcards
Give 3 examples of areas of study that benefit from GIS
City and Regional Planning
Hydrologic Modeling
Security
Geotechnical Engineering
Transportation
Marketing
Real Estate
Business
Politics
Environmental Studies
discrete vs continuous data
discrete objects: objects exist in a defined location
continuous: data exist everywhere
What is the kind of data that exists in a defined location?
discrete
Define discrete data and give two examples
Discrete data are objects in the real world with specific locations or boundaries. Examples include houses, cities, roads, countries, canoe shelter locations
What is the name for data that exists anywhere?
Continuous
Canoe shelter locations is an example of what kind of data?
Discrete
Define continuous data and give two examples
Continuous data represent quantities that may be measured anywhere on the earth. Two examples include temperature or elevation
An elevation raster is an example of what kind of data?
continuous
What are stored map objects?
features
What are features and what three basic shapes do they consist of? Give an example of a feature
A spatial object composed of one or more XY pairs and having one or more attributes in a single record of an associated table. Features can be lines polygons or points.
Examples of features include a point feature representing a well or weather station, a line feature representing linear object like a rotor River, a polygon feature representing a closed area like a country or state
What is a collection of similar features with the same attributes stored together in a spatial data file, like states or rivers?
feature class
What is a feature class and give an example
A set of similar features stored together for example a United States feature class comprising of the 50 states
___ is a a set of similar objects with the same attributes stored together in a spatial data file
feature class
In the ____ model, Spatial features linked to table by unique identifier (FID or OID)
vector
What is the vector model
A spatial data storage method in which features are represented by one or more pairs of XY coordinate values forming points lines or polygons
In the ____ model, Geographic space is quantized into uniformly-sized discrete units, called pixels or cells
raster model
What is a raster
A data set composed of an array of numeric values each of which represents the condition in a square element of ground
Name at least two strengths of the vector model:
Can store individual features such as roads or streams with a high degree of precision
Linked attribute table provides capability to store and manipulate feature attributes
Suitable for mapmaking due to great feature detail
Ideal for network modeling
What is a weakness of the vector model?
Poorly suited to map continuous data
Some analysis can be time consuming (updating county level parcel data)
_______ is the ratio of distance on the map to distance on the ground
map scale
A ____ scale map covers a larger geographic region such as the world
small
a ___ scale map covers a relatively small geographic area
large
Does a small-scale map cover a large or small geographic area?
large
Does a large-scale map cover a large or small geographic area?
small
A ___ scale map is one in which the ratio is large
large. Thus, a 1:24,000 scale map has a larger scale
than a 1:100,000 scale map. A large-scale map shows a relatively small
area, such as a city, whereas small-scale maps show bigger areas, such
as states or countries.
______ describes how closely the x-y values of a data
set correspond to the actual locations on the earth’s surface.
Geometric accuracy
What is geometric accuracy and give an example of when geometric accuracy might be compromised
Accuracy that describes how closely the XY values of the data set correspond to the actual locations on the Earth’s surface. Maps derived from aerial photography can vary wildly in geometric accuracy based on factors such as image scale, resolution, imperfections and distortions in the imaging system, and corrections applied to the image.
______ refers to how accurate the attributes stored in the table are to real life
Thematic accuracy
What is thematic accuracy. Give an example of when thematic accuracy might be compromised
The degree to which attribute values represent the true properties in the real world.
Population data can never be 100% thematically accurate because it is collected through process of surveying and self reporting over many months during that time people are born and die or move.
What is logical consistency. Give at least two examples of logical consistency.
It evaluates whether a data model or data set accurately represents the real-world deletion ships between features.
In the real world, to adjacent states share a common boundary that is exactly the same in a database however the states might be stored as two separate features with slightly different boundaries.
Lines representing streets should connect if the roads they represent meet. Counties should not extend past the boundary of their states.
____ stores information about the
data set, such as where it came from, how it was developed, who
assembled it, how precise it is, and whether it can be given to another
person.
metadata
What is metadata
Stores information about the data set such as where it came from how it was developed who assembled it how precise it is and whether it can be given to another person
What is information about map features stored in columns of a
table?
attributes
What are attributes? Give at least two examples of possible attributes were a state feature
information about map features stored in columns of a table
examples include a states name, abbreviation, population, area, etc.
___ evaluates whether a data model or data set accurately represents the real-world relationships between features.
logical consistency
What is a database?
a data construct designed to store information as tables
____ is the analysis of spatial data layers, such as dissolving, intersecting, and merging
geoprocessing
What is geoprocessing
the analysis of spatial data layers, such as dissolving, intersecting, and merging
What is a spatial data layer that is tied to a specific location on the earth’s surface for display with other data?
georeferenced data
What is georeferenced data?
a spatial data layer that is tied to a specific location on
the earth’s surface for display with other data
____ is information stored about data to document their source,
history, management, uses, and more
metadata
What is metadata?
information stored about data to document their source,
history, management, uses, and more
Thematic accuracy is not related to data location
T
Thematic accuracy is related to the accuracy of the attributes. Geometric accuracy is related to a feature’s location
T or F
Logical consistency assesses how well data represents real-world relationships
T
For example, do roads connect at intersections? Do county and state boundaries align?
When GIS servers provide data over the internet (streaming data), this is an example of a
map service
Match the data type with the map type
Nominal
Numeric (Interval and Ratio)
Categorical
Single Symbol
Graduated Symbol and Graduated Color
Unique Values
Nominal-single symbol
Categorical-unique values
numeric-graduated symbol
T or F
Data or Numeric Classification applies only to vector data
F
Correct. Data or Numeric Classification applies to vector and raster data. Numeric raster data can be classified (elevation ranges)
Quantile classification puts the same number of features into each class
T
MAUP stands for
Modifiable Areal Unit Problem
In an attribute table, dividing each value by the total of all the values is another way to _____________ data
normalize
____ maps are used for nominal data
Single symbol
___ maps are used for categorical and ordinal data
unique values
Many types of maps are used for ___ data
numeric
Give an example of a type of map used for numeric data
Graduated color maps.
Graduated symbol maps.
Dot density maps.
Chart maps
What map types can a thematic map uise?
unique value, graduate colors or symbols, dot density, charts)
Unique values maps are used for _____ and ____ data
categorical and ordinal
Single symbol maps are used for ____ data
nominal
____ maps are used for numeric data
many (graduated color/symbol, dot density, charts)
What is nominal data?
Data that names or uniquely identifies objects
Give an example of nominal data
country names, capital cities, rivers, water bodies
How are nominal data usually portrayed?
single symbol map
What is categorical data and give an example.
Data where features belong to categories.
Rock types, volcano types, highway classes, land cover class
What kind of map is used to portray categorical data?
unique values map
What is ordinal data and give an example
a type of categorical data where the categories are ranked along a scale.
ex. Tree Planting Potential:
(0) Unsuitable
(1) Marginal
(2) Acceptable
(3) ideal
Country names (labelled)
Capital Cities (stars)
Rivers (labelled)
Water bodies
This is an example of what kind of data?
nominal data
What kind of map is used for ordinal data?
a unique values map with a single-hue color scheme
What is numeric interval data & give an example.
numeric data that places values along a regular numeric scale. It includes negative numbers.
elevation along the Georgia Coast (includes below sea level), temperature, population change
What is the only kind of numeric value that can have negative values?
interval numeric data
What is Numeric ratio data? give an example
data places values along a regular scale with a meaningful zero point (no negative values)
Population of state capitals.
What kind of numeric data cannot be negative?
ratio data
What method of classifying data uses Jenks Optimization method?
Jenks Natural Breaks classification
What is Jenks Natural Breaks classification?
a way to classify numeric data into ranges defined by
naturally occurring gaps in the data histogram
What method of classifying data produces equal sized classes?
Defined interval or equal interval classification
What is defined interval classification?
a classification method in which the user specifies a
size range for all the classes
The ____ classification puts the same number of features in each class (linear data distribution)
quantile
What is quantile classification?
a classification method that divides the data into the
specified number of quantiles so that each class has the same number of features
The _____ classification compares values close to and far from the mean (always show mean and std on map
standard deviation
What is standard deviation classification?
a classification scheme in which the class breaks
are based on the standard deviation values of the data being mapped
______ rasters use unique values or discrete color display
Categorical/ordinal
Categorical/ordinal rasters use _____ or ______ display
unique values, discrete color
__________ rasters use classified or stretched display methods
Interval/ratio (quantities)
Interval/ratio (quantities) rasters use _____ or ______display methods
classified, stretched
____ data name things or uniquely identify them and may be
text or numbers.
nominal
______ data group objects into smaller sets identified by a
unique value.
Categorical
_______data consist of categories that are ranked in some
way.
Ordinal
_____data are measured on a regular scale, and data are measured on a regular scale with a meaningful zero point.
Interval, ratio
Discrete thematic rasters can be displayed using what method?
unique values method
What rasters may be classified or stretched?
Continuous thematic
What kind of data that place objects into unranked groups?
categorical data
land use and geology data are examples of what kind of data?
categorical
What is classification?
assigning features to two or more groups based on
numeric values in an attribute field
a classification method that bases the class
intervals on a geometric series in which each class is multiplied by a
constant coefficient to produce the next higher class
geometric interval
What is geometric interval classification?
a classification method that bases the class
intervals on a geometric series in which each class is multiplied by a constant coefficient to produce the next higher class
T or F
Geographic coordinate systems are based on spherical coordinates and measured in latitude and longitude
T
T or F
A geoid shifts the ellipsoid relative to the datum to achieve a best fit between the two
F
A datum shifts the ellipsoid relative to the geoid to achieve a best fit between the two
Three Types of Projections are _____ , ____, and ______.
Azimuthal, cylindrical, conic
Projections all distort one or more properties of
______ , ______, _______, and ________
distance, direction, shape, area
T or F
UTM coordinate system breaks the world up into 6 zones of 60 degrees each
F
UTM coordinate system breaks the world up into 60 zones of 6 degrees each
Match the type of coordinate system to the definition:
Unprojected
Projected
Based on spherical coordinates
Converts spherical coordinates to planar coordinates
Unprojected (geographic)- Based on spherical coordinates
Projected- Converts spherical
What is a datum
shifts the ellipsoid relative to the geoid to achieve a best fit between the two.
what is a projection?
a mathematical conversion of points on the earth’s surface to a flat plane (map)
a common coordinate system for large-scale maps is?
UTM coordinate system, state plane CS
What is the Spatial Reference
Proper alignment of data sets requires that each one have a label that records the complete coordinate system parameters
This label is called the spatial reference
What is the Project tool?
used to permanently convert a data set from one coordinate system to another
________creates a new data set in the new coordinate system
projection
What is the Define Projection tool?
Create the missing label for the true coordinate system of a map with the tool
what tool Use only when CS is missing or incorrect?
define projection
What tool should be used when changing a CS permanently?
project tool
What tool is use to assemble collections of data with the same stored CS.
project tool
What is the extent?
he range of x-y coordinates of the features actually in the feature class displayed in a map or stored in a data layer
Values between +180
and –180 indicate an ______GCS coordinate system with map
units in degrees, whereas large values indicate a ______ coordinate
system with units of feet or meters.
unprojected, projected
What is the x-y precision in the spatial referencfe?
resolution
Two types of vector data formats are _____and ____
geodatabase and shapefiles
Choose all possible answers - which methods are used to extract or subset data from a dataset?
queries
manual selection
project
clip
manual selection, clip
T or F
Streaming data or GIS web services are datasets stored on your local computer
F
T or F
Shapefiles consist of more than one file
T
Shapefiles consist of, at minimum, a .shp, .dbf, and .shx
A _______can be a point, line, or polygon and represent an vector object or location on a map
feature
What is a feature dataset?
stores feature classes that have the same coordinate system and the same spatial extent
what is a feature class and give an example
a homogeneous collections of features with a common spatial representation and set of attributes stored in a database table, for example, a line feature class representing road centerlines.
what is a geodatabase
A geodatabase is the native data structure for ArcGIS and is the primary data format used for editing and data management.
What corresponds to or can be represented by a shapefile?
feature class
What is a collection of related feature classes that share a common coordinate system
Feature Dataset:
What is the difference between a feature class and a feature dataset?
A feature class is collection of common features, each having the same spatial representation—such as points, lines, or polygons—and a common set of attribute columns. A feature dataset is a collection of related feature classes that share a common coordinate system
_____ are used to extract data using an expression based on an attribute field
Queries
What is a query? Give an example
an operation to extract records from a database according to a specified set of criteria
an example of attribute query is a population greater than hundred thousand
an example of a spatial query is parcels that are in a floodplain
What is the difference between an attribute and spatial query
In an attribute query expression is used to find records with values meeting a specified condition
spatial query spatial relationship between two layers is evaluated
What do we call the tables rows and columns
Rows are called records
columns are called fields or attribute fields
What are arithmetic operators and give example
Arithmetic operators are part of queries and act on numbers
3+5
What are logical operators and give an example
Logical operators test conditions in return true or false. They are part of GIS queries.
ex. STATE = NJ, GPA > 3.0
_____combines all features from two or more data sets into a single new feature class
Merging
In what circumstances does merging work best?
When two adjacent feature classes have attribute tables with the same fields
_____ removes boundaries of features with the same value in the specified attribute field(s)
Dissolving
Give 3 examples of data types used in ArcGIS
shapefiles, tiffs, geodatabases, database connections, layer files, tables, TIN, CAD drawings
The blank data model stores features but it also contains information about how the features are spatially related to each other
Topological
The dimensions of a pixel is the
resolution
What are the benefits of using the raster model
Veterans during certain kinds of data (continuous), better analyzing certain types of data, often faster analysis than vectors, imagery desirable for certain maps
What are the drawbacks of the raster data model
Coordinate precision is generally lower than the vector model, high precision has high storage costs, cannot store multiple attributes
Give one example of a raster type
Digital elevation model (DEM), color aerial photograph, land-use categories, scanned topo map or digital raster graphic, arc GIS online base map tile, roads
_____ is changing the resolution of a raster, producing a new copy
Resampling
_______ groups pixels and determines the new value using a statistic
Block resampling
_______ grabs the value from the old cell that falls at the center of the new cell. It preserves the original value and should always be used with categorical data, or when the original data values need to be preserved. It is the fastest method
Nearest neighbor resampling
______ calculates a new value from the four cells that fall closest to the center of the new cell. It uses a distance-weighted algorithm based on the old cell centers. It is best used with continuous data such as elevation
Bilinear resampling
______ calculates a new value from the sixteen cells that fall closest to the center of the new cell. It uses a distance-weighted algorithm based on the old cell centers. It is best used with continuous data such as elevation. It is the most time-consuming method
Cubic convolution resampling
Give an example of a time when resampling is required in the raster data model
When projecting rosters or when analyzing two wrestlers with different resolutions
______rasters store values representing measurements or categories and can be analyzed.
______ rasters store color values (like taking a picture of a map) and cannot be analyzed
Data, Picture
Give an example of a data raster
Elevation, aerial imagery, land-use, roads
Give an example of a picture Raster
Scanned topo map, base map
_____is a special value used in some raster formats to indicate absent data
NoData
______ creates a real-world coordinate system for an image
that lacks one, usually because it is a map picture or scan. A
_______session starts by adding the data with a real-world
coordinate system, the reference layer, first. Then add the image.
Georeferencing x2
In a table, rows are called ____
and columns are called ____
Records, fields
T or F
In arc GIS Pro, there are five basic field types for a table
F
T or F
Tabular joins are permanent
F
T or F
In a Many to One join, one record in the target or destination table matches many records in the join or source table.
F
Assuming the target table is on the left, states to cities is an example of which type of cardinality?
1:1
1:M
M:1
M:M
M:1
What are the two main types of GIS tables
Attribute tables and standalone tables
___ tables store data associated with aspatial feature class
Attribute tables
______ tables simply stores tabular data from any source
Standalone table
The structure of a table, including its fields, their definitions, its domains, and so on, are called the table _____
schema
Name at least two of the arc GIS field data types
Short and long integers, float and double decimal values, text, date
Are short and long field data types for integers or decimal values?
Integers
Are float and double field data types for integers or decimal values
Decimal values
255 is an example of what field data type?
Short
156000 is an example of what field data type?
Long
1.289385e12 is an example of what field data type
Float
‘John H. Smith’ is an example of what field data type
Text
07/12/2008 is an example of what field data type
Date
