• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/49

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

49 Cards in this Set

  • Front
  • Back

GIS definition

Geographic Information System:


Computer based system to aid in the collection, maintenance, storage, analyzation, output, and distribution of spatial data/info.



6 Aspects of GIS

Data, Software, Method, People,


Network, Hardware




Did Some Man Poop Near Here

Aspects of Hardware

Computers


Input


Printing


Disk Space

Aspects of Network

Dissemination of data


Display of info

Aspects of Methods

Formulas


Statistics


Analysis


Algorithms

Aspects of Software

Provides:


Manipulate


Store


Query


Analyze data

What is the Geospatial Data Model

Formal means of representing spatially referenced data

What are the 2 different Spatial Phenomenons and their definitions

Discrete - Individually Distinguishable and does not exist between observations (ex: lakes, rivers)




Continuous - exists between observations (ex: temperature, elevation)

4 different types of attributes (catagorial)

Nominal


Ordinal


Interval


Ratio

Nominal attribute

Naming that does not imply rank or order or size




Just naming (ex. movie name, color, plant type)

Ordinal attribute

implies rank/order but not scale

Interval Attribute

implies rank/order and scale but no natural zero (ex. temperature, can be added but not multiplied)

Ratio Attribute

Rank, order, and magnitude, has natural zero


(ex. mph, height)

Identify


(A) (B) (C) (D)


ID height(ft) Type Class


1 15 pine Med


2 20 pine Med


3 8 mesquite Small


4 30 oak Tall

A) = Nominal


B) = Ratio/interval


C) = Nominal


D) = Ordinal



Attribute Data Types (number)

The data type of the attribute needs to be specified for the efficient use of memory and determination of the operation applicability.




Integer


Float/real


Text/String


Date

Integer attribute

whole numbers

Float/Real Attribute

numbers with decimals

Text/string attribute

numbers and letters but can't be used to calculate (aka a address)

Date

Dates (12/25/2015

What are the three Spatial Data Models

Raster


Vector


Triangulated Irregular Network (TIN)

Vector Data Models + 3 basic vector types

Defines Discrete models




types: points, lines, and polygons




Composed of coordinates and attributes

Point

Uses a single coordinate, no dimension


(ex: light poles, manholes)

Lines:


-node


-vertex

Uses ordered set of coordinates


Each line (& curve) is made up of multiple line segments, occasionally curves are represented mathematically




node= starting point


vertex= intermediate point of line




(ex: road, pipeline, outlines, river)

Polygons

Formed by set of connected lines




Must close




Have interior region


(ex: lake, city, tree stand, political boundary)

What is a Raster Model

Represents continuous objects (ex: temp. elevation)




Regular set of cells in a grid (matrix)




Real-world objects are represented by values in the grid cells

Raster vs. Vector

Raster

- Good for frequent changes - Simple


- Easy Overlays - Best for digital imagery




Vector


- Compact - Great for network and linear features


- People are more familiar with vector


- Can obtain topo



What is a TIN - triangulated irregular networks

A network of triangles connected by 3D surface


- triangles do not cross




More complex than rasters (More efficient space-wise)




TIN preserves each measurement point



(A) Two types of data sources

A). Hardcopy and Digital


Hardcopy is stable cheap portable but reusable and not easily updatable.


Digital is cheap, stable, updatable but its not portable, requires hardware that may be specific

Coordinate Transformation aka Registration

aka georectification



Brings spatial data into an Earth-based map coordinate system using control points

What is are Control Points def. and guidelines

Used to transform data from digitizer coord. system to map coord. system




1. Should provide highest accuracy


2. Accuracy should be good positional accuracy


3. Should be evenly distributed



From previous maps and land surveys

What is Digitizing

process of converting coordinates of features from a data source into digital format




methods:


1. manual


2. automatic

What is are the two Digitizing errors

overshooting the vertices or nodes


undershooting the vertices or nodes

Manual versus Automatic digitizing

Manual

pro:


- accurate - Short training - Humans interpret better


- lower initial capital (no programer)


con:


map scale, operator, and equipment impacts accuracy




Automatic


pro:


- good for large projects


- no initial operator cost - works well with large # of operators


cons:


- expensive - requires manual editing


- only translates, not interpret - scanner errors







What is Feature Generalization

approx. and simplification of real features when represented on a map



What are the Methods of Generalization

Fused


Simplified


Exaggerated


Displaced


Omit



Map def. and purpose

Definition:


A graphic representation of a milieu


Milieu = cultural and social impacts




Purpose:


Way to transmit knowledge



Different types of Maps

Reference = emphasis on location, political map (roads maps)




Thematic = Emphasis on attributes, show one subject, one theme (ex: educational level, political affiliation)

Two types of thematic maps

Qualitative = show nominal data (time zones)




Quantitative = show numerical data, variation from place-to-place (population density, political map)

Cartographic Process/Define steps after seeing them

1. Define purpose and meaning


2. Choose scale


3. Determine map format, limitations printing, and economics of re/production


4. Abstract and generalize (only meaningful info, organize necessarily to communicate well, keep simple)


5. Design Layout (scale, title, legend, inlet map, credits)

Map Scales

Large Scale = 1:0 - 1:600,000


Med. Scale = 1:600,001 - 1:2,000,000


Small Scale = 1:2,000,001 - 1:infinite

Four methods to abstract and generalize

Selection


Classification


Simplification


Symbolization

Graticule

Visual representation of coordinate system or location scheme

NSDI

National Spatial Data Infrastructure

DRG

Digital Raster Graphic (Georeferenced double check tool)

Digital Orthophoto Quadrangle (DOQ)

Scanned photos (raster) backgrounds

Map Properties (4)


Major and minor

Can have one or more perfect but not all four


Major: Mutually exclusive


- Area


- Shape




Minor Properties: Cannot exist all of the time


- distance


- direction

Maps that preserve Area (equivalent maps)

Albers Equal Area


Sinusoidal

Maps that preserve shape (conformal Map)

couldn't tell

preserves neither shape or area

Goodes Homolosine Map


Robinson Map