GIS

Card Set Information

Author:
ichiban2008
ID:
172555
Filename:
GIS
Updated:
2012-09-24 13:35:56
Tags:
GIS
Folders:

Description:
GIS TEST 1
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user ichiban2008 on FreezingBlue Flashcards. What would you like to do?


  1. Basics
  2. Cartography
    the art and science of producing maps
  3. Basic Themes
    political, reference, topographic
  4. Topographic Maps
    US geological survery started in 1879

    maps made by planetable surveying

    photogrammetry (science of measuring and interpreting photos) in 1940s

    defined by their contour lines to portray shape and elevation of the land

    lines drawn representing constant vertical height above sea level

    CONTOUR INTERVAL - change in vertical height between two adjacent contours; same on a simgle map
  5. Contour Interval
    change in vertical height between two adjacent contours; same on a simgle map
  6. GIS
    computer system for capturing, storing, quering, analyzing, and displaying geospatial data
  7. GISc
    science

    the theory behind the development, use, and application of GIS
  8. GIST
    technology

    always changing and improving

    spatial data, attritube data

    strength is it handles and processes geospatial data

    geospatial data: describes both the locations and characteristics of spatial features
  9. geospatial data
    describes both the locations and characteristics of spatial features
  10. Components of GIS
    computer system, GIS software, people, data, infrastructure
  11. Vector Data
    points, lines, polygons

    uses x,y coordinates to represent point features

    • points: have no dimenstions; single x,y coordinate
    • lines: have one dimension, length, with beginning and ending nodes and intermediate points called vertices
    • polygons: have two dimensions, length and area; consist of a  group of verticies that define a closed area
  12. Raster Data
    uses cells in a grid to represent point features

    • discrete data (usually thematic or categorical data)
    • thematic raster: land use and land cover
    • continuous data: temp, elevation, aspect
  13. Scale
    • Small Scale: map that covers a large area, but gives little detail
    • 1:2,000,000

    • Large Scale: map which covers a small area and provides a lot of detail
    • 1:50,000
  14. GISS Intro
  15. oldest map
    Babalonian Clay Tablet World Map

    600 bc

    • early maps were hand drawn 
    • wood carvings were used to reproduce the early maps
  16. Grandfather of Remote Sensing
    Gaspard Nadar Tournachon
  17. Dr. Roger Tomlison
    father of GIS

    developed GIS for the Canadaian Land Inventory
  18. ESRI
    Environmental Systems Research Institute

    formed in 1969 by Dangermond

    GPS made public in 2000

    • today, more than 90% of GIS market uses ESRI
    • 3+ billion anual revenues-debt free company
  19. GIS links _____ data with _______ data
    Aspatial Data- data that is not tied to a location on the earths surface


    Spatial Data- information that is tied to a specific location on the earths surface
  20. With GIS you can:
    • create maps, graphs, reports
    • manage map data
    • analyze spatial relationships
    • overlay map data from different sources
    • manage and display database info
    • locate addresses
    • analyze utility and transportation networks
  21. What is a map
    a graphic representation of the spatial relationships of entities within an area

    a depiction of all or part of the earth or other geo phenomenon as a set of symbols and at a scale whose representative fraction is less than 1:1
  22. Vector Data Model
  23. ESRI Data Models
    coverage and shapefiles use split systems to store geometries and attributes
  24. DBF, PRJ, SBX, SBN, SHX, XML
    • dbf: database
    • prj: projection
    • sbx: spatial index
    • sbn: spatial index format
    • shx: shape index
    • xml: metadata
  25. Topology
    diagrams or graphs are used in topology to study the arrangements of geometric objects and the relationships between objects
  26. Topology Advantages
    • ensures data quality
    • are lines connecting?
    • coincident boundaries have no gaps or overlays


    it can enhance GIS analysis when using geocoding
  27. Georelational Data Model
    stores geometries and attribues seperately in a split system

    examples being coverage and shapefiles
  28. Shapefiles
    standard, nontopological data format used in ESRI

    treates a point as a pair of x,y coordinates, a line as a series of points, and a polygon as a series of line segments, but there are no files to describe the spatial relationships between these geometric objects
  29. Advantages of NonTopo Vector Data
    display more rapidly on a computer monitor than topo based data

    more nonproprietary and interoperabe, meaning that they can be used across different software packages
  30. Geodatabases
    part of ArcObjects, a collection of thousands of objects, properties, and methods that provide the foundation for ArcGIS 

    defines topo as relationship rules and lets user choose the rules, if any, to be implemented in a feature dataset
  31. Geodatabase Advantages
    data orginization and management: create feature dataset to hold all feature layers for specific areas; new data has same coordinate system

    provides object oriented tech such as domains and validation rules

    on the fly topology to ensure data integrity and optimize data analyses

    can develop customized application using Python
  32. TIN
    triangulated irregular networks

    approximates the terrain with a set of nonoverlapping triangles
  33. Routes
    a linear feature such as a highway, a bike path, or a stream but unlike other linear features, a route has a measurement system that allows linear measures to be used on a projected coordinate system
  34. Raster Data Model
  35. Raster Data
    uses a grid to cover the area

    value of each grid cell represents value of characteristic at that cell location

    data storage: divided into rows, colums, and cells

    can represent a discreet or continous surface

    represents points by single cells, lines by sequences of neighboring cells, and areas by collections of contiguous cells
  36. Elements of Raster
    Cell Value: represents characteristic of a spatial phenomenon at location denoted by its row and column

    • cell value can be integer or floating point
    • intergers used for discrete (land use or habitat suitability)
    • floating used for continous (temp, precip, elevation)

    Cell Size: determines resolution of raster data model

    • smaller cell size gives greater ability to distinguish features on the landscape
    • 3 meters per cell = high resolution
    • 30 meters per cell = not as good resolution

    Raster Bands: singular or multiple

    Georeferenced Raster: one that has been processed to match a projected coordinate system

    Spatial Reference: aligned spatially with other data sets in a GIS
  37. Types of Raster
    • sttellite imagery
    • digital elevation modesl DEM
    • digital orthophotos quads DOQ
    • digital orthophoto quarter quads DOQQ
    • bi level scanned files
    • digital raster graphics DRG
    • digital line graphics DLG 
  38. Header Files
    contains info required by ArcGIS

    • data structure
    • extent (rows and columns and spatial extent)
    • cell size
    • number of bands
    • value for no data
  39. Data Compression
    raster data are usually large files and require large computer storage

    data compression refers to the reductin of data volume

    a variety of techs are available for image compression.  compression techs can be lossless or lossy

    • TIFF - lossless
    • Jpeg - lossy
  40. Data Conversion
    converstion of vector data to raster data is called rasterization
  41. three steps of Rasterization
    • creation of raster grid with specific cell size
    • change values of cells that correspond to points, lines, or polys
    • fill the interior of polys with poly value
  42. Four Steps of Vectorization
    • line thinning (lines may be more than one cell)
    • line extraction (determine where lines begin/end)
    • topological reconstruction (make certain all lines are connected)
    • line smoothing (remoes step like fetures)
  43. Map Symbology
  44. Components (7)
    • title
    • map
    • legend
    • scale bar
    • north arrow
    • source
    • ancillary info
  45. Principles
    • maximize size of map relative to other components
    • balance elements on the page
    • avoid blank or cluttered areas
    • align straight edges 
    • use neatlines to enhance clean lines
    • choose quite patterns (dont use same pattern for land and water)
    • use natural colors
    • emphasize import info
  46. Geographic Coordinate System
    2 Dimensions:

    Lat and Long

    North/South Pole are the fixed reference points

    Equator and poles most important when dealing with the Corrdiante system

    Measured in Degrees, Minutes, Seconds

    Prime Meridian located in Greenwich, England

    • Total of 360 Degrees
    • 60 Minutes in each Degree
    • 60 Seconds in each Minute

    3600 seconds in each degree

    Converts into Decimal Degrees
  47. Convert into Decimal Degrees

    38 48 41.17
    • add decimal to degrees
    • 38 degrees becomes .38

    • divide mintes by 60
    • 48/60
    • .8

    • divide seconds by 3600
    • 41.17/3600
    • .011436

    • Add all together
    • 38+.0+.011436
    • 38.81144
  48. Circle to Rectangle

    Geoid Anomalies
    Topographic Variations

    Polar Flattening

    Gravitational anomalies
  49. Clark 1866
    ground measured spheroid used for mapping til the late 1980s
  50. GRS 80
    satellite determined spheroid

    shape, size and measurements of earth determined through Doppler satellite
  51. Datum
    mathematical model of earth used as reference for calculating geogrpahic coordinates

    includes point of origin that models earth in a regional context

    used to reduce discrepencies
  52. Top three datums
    • NAD27
    • based off clark 1866
    • used for digital and paper maps
    • origin is Kansas lol

    • NAD83
    • based on GRS80
    • used for paper maps
    • origin is center of earth

    • WGS84
    • used by DOD
    • based on GRS80
    • most precise
    • used for GPS data
    • Origin is center of earth
  53. UTM
    uses linear measurment of meters

What would you like to do?

Home > Flashcards > Print Preview