GIS Tutorial 1 Lecture 5 Importing spatial and

GIS Tutorial 1 Lecture 5 Importing spatial and attribute data

Outline § Map projections § Coordinate systems § GIS data sources § Vector data formats § Raster data formats GIS TUTORIAL 1 - Basic Workbook 2

Lecture 5 MAP PROJECTIONS GIS TUTORIAL 1 - Basic Workbook 3

Latitude and longitude u Longitude (meridians) GIS TUTORIAL 1 - Basic Workbook 4

Latitude and longitude u Latitude (parallels) GIS TUTORIAL 1 - Basic Workbook 5

Latitude and longitude 0 ° Longitude (prime meridian) 0 ° Latitude (equator) GIS TUTORIAL 1 - Basic Workbook 6

Latitude and longitude u Coordinates Pittsburgh, PA USA 40 -80 GIS TUTORIAL 1 - Basic Workbook 7

Lat/Long coordinates u Degrees, minutes, and seconds (DMS): § 40° 26′ 2″ N latitude § -80° 0′ 58″ W longitude u Decimal degrees (DD) § § § 1 degree = 60 minutes, 1 minute = 60 seconds 40° 26′ 2″ = 40 + 26/60 + 2/3600 = 40 +. 43333 +. 00055 = 40. 434° GIS TUTORIAL 1 - Basic Workbook 8

Lat/long coordinates Translated to distance u World circumference through the poles is 24, 859. 82 miles, so for latitude: § 1° = 24, 859. 82 / 360 = 69. 1 miles § 1′ = 24, 859. 82 / (360 * 60) = 1. 15 miles § 1″ = 24, 859. 82 * 5, 280 / (360 * 3, 600) = 101 feet u Length of the equator is 24, 901. 55 miles GIS TUTORIAL 1 - Basic Workbook 9

Mercator projection (1569) § Conformal projection § Cylindrical § Parallels and meridians at right angles § Linear scale is constant in all directions around any point § Preserves angles and shapes of small objects § Distorts the size and shape of large objects § Map projection for nautical purposes GIS TUTORIAL 1 - Basic Workbook 10

Hammer – Aitoff (1882 -1889) § Equal-area § Modified azimuthal projection § Good for population density (world area) § Difficult to see some areas GIS TUTORIAL 1 - Basic Workbook 11

Robinson projection (1961) § Pseudocylindrical § Neither equal area nor conformal § Meridians curve gently, avoiding extremes § Good compromise projection for viewing entire world § Used by Rand Mc. Nally since the 1960 s and by the National Geographic Society (1988 and 1998) GIS TUTORIAL 1 - Basic Workbook 12

Albers Equal Area § Conic projection § Scale and shape are not preserved, distortion is minimal between the standard parallels § Standard projection for British Columbia, U. S. Geological Survey, U. S. Census Bureau GIS TUTORIAL 1 - Basic Workbook 13

Projection important § Measurements used to make important decisions § Comparing shapes, areas, distances, or directions of map features § Feature and image themes are aligned New York Los Angeles Projection: Mercator Distance: 3, 124. 67 miles Projection: Albers equal area Distance: 2, 455. 03 miles Actual distance: 2, 451 miles GIS TUTORIAL 1 - Basic Workbook 14

Projection not important u Business applications § Not of critical importance § Concerned with the relative location of different features u On large scale maps—street maps § Distortion may be negligible § Map covers only a small part of the earth’s surface GIS TUTORIAL 1 - Basic Workbook 15

Lecture 5 COORDINATE SYSTEMS GIS TUTORIAL 1 - Basic Workbook 16

Geographic Coordinate System (GCS) § Spherical coordinates § Angles of rotation of a radius anchored at earth’s center § Latitude and longitude § Census Bureau TIGER files GIS TUTORIAL 1 - Basic Workbook 17

U. S. Census GCS example GIS TUTORIAL 1 - Basic Workbook 18

Rectangular coordinate system § Used for locating an intersection on a flat sheet of graph paper or a flat map § Cartesian coordinates (x, y) § State plane and UTM GIS TUTORIAL 1 - Basic Workbook 19

State Plane coordinates § Established by the U. S. Coast and Geodetic Survey in 1930 s § Originally North American Datum (NAD 1927) § More recently NAD 1983 and 1983 HARN § Used by local U. S. governments § All positive coordinates in feet (or meters) GIS TUTORIAL 1 - Basic Workbook 20

State Plane zones § 125 zones At least one for each state q Cannot have zones joined to make larger regions q § Follow state and county boundaries § Each has its own projection: Lambert conformal projection for zones with east-west extent q Transverse Mercator projection for zones with north-south extent q GIS TUTORIAL 1 - Basic Workbook 21

State Plane zones GIS TUTORIAL 1 - Basic Workbook 22

State Plane zones GIS TUTORIAL 1 - Basic Workbook 23

Pittsburgh neighborhoods as state plane coordinates GIS TUTORIAL 1 - Basic Workbook 24

Universal Transverse Mercator (UTM) § Rectangular coordinate system § Used by U. S. military § Covers entire world § Metric coordinates § Longitude zones are 6° wide § Latitude zones are 8° high GIS TUTORIAL 1 - Basic Workbook 25

Coordinate system summary u Geographic coordinate system § U. S. Census u State plane coordinate system § Local governments § U. S. military u u Projections defined in Arc. Catalog or Arc. Map (. prj) files First file added in a map document sets the projection (others will adjust to it as long as they have a. prj file) GIS TUTORIAL 1 - Basic Workbook 26

Lecture 5 GIS DATA SOURCES GIS TUTORIAL 1 - Basic Workbook 27

GIS data sources u u u ESRI U. S. Census USGS and other government sources GDT Dynamap/2000 U. S. Street Data Engineering companies q u u land surveys, aerial photos, CAD drawings University Web sites (e. g. Penn State’s PASDA) Others? GIS TUTORIAL 1 - Basic Workbook 28

GIS data sources u 30+ million Internet search results § type “GIS data download” or “population China . e 00 § add the name of the state, county, or city to the search GIS TUTORIAL 1 - Basic Workbook 29

GIS departments Web sites u Washington, D. C. § dcgis. dc. gov/ u Chicago, IL § www. cityofchicago. org/gis u Austin, TX § Tip: Search by county name (Travis County, Texas) q q http: //www. ci. austin. tx. us/development/ ftp: //ftp. ci. austin. tx. us/GIS-Data/Regional/coa_gis. html GIS TUTORIAL 1 - Basic Workbook 30

ESRI’s Web site u http: //www. esri. com/data/resources/geograp hic-data. html GIS TUTORIAL 1 - Basic Workbook 31

U. S. Census Bureau u u Started building a map infrastructure in the late 1970 s and early 1980 s Census mapping needs were twofold: § To assign census employees to areas of responsibility, covering the entire country and its possessions § To report and display census tabulations by area, officials determined that the smallest area needed for these purposes is a city block or its equivalent GIS TUTORIAL 1 - Basic Workbook 32

U. S. Census Bureau u u Compiles all line features used to create a block layer for the entire country Map features smaller than are the responsibility of local governments § § § deeded land parcels buildings street curbs parking lots others? GIS TUTORIAL 1 - Basic Workbook 33

Census TIGER/Line files u Topologically Integrated Geographic Encoding and Referencing files § Census Bureau’s product for digital mapping of the U. S. § Available for the entire U. S. and its possessions § Include the following geographic features q roads and street centerlines q railroads q rivers q lakes q census statistical boundaries GIS TUTORIAL 1 - Basic Workbook 34

TIGER census tracts u Statistical boundary (below county level) § between 1, 000 and 8, 000 people (in general) § 1, 700 housing units or 4, 000 people § homogeneous population characteristics (economic status and living conditions) § normally follow visible features § may follow governmental unit boundaries and other nonvisible features § more than 60, 000 census tracts in Census 2000 GIS TUTORIAL 1 - Basic Workbook 35

PA tracts GIS TUTORIAL 1 - Basic Workbook 36

Allegheny County tracts GIS TUTORIAL 1 - Basic Workbook 37

City Pittsburgh tracts GIS TUTORIAL 1 - Basic Workbook 38

TIGER census block groups u Subdivision of a census tract § 400 housing units, with a minimum of 250 and a maximum of 550 housing units § Follow clearly visible features such as roads, rivers, and railroads GIS TUTORIAL 1 - Basic Workbook 39

Census block groups GIS TUTORIAL 1 - Basic Workbook 40

TIGER census blocks u Smallest geographic area for which the Census Bureau collects and tabulates decennial census information § Visible boundaries q q street road stream Shoreline § Nonvisible boundaries q q county, city, neighborhood boundary property line GIS TUTORIAL 1 - Basic Workbook 41

Census blocks GIS TUTORIAL 1 - Basic Workbook 42

Other TIGER layers GIS TUTORIAL 1 - Basic Workbook 43

U. S. Census Bureau data tables u http: //factfinder. census. gov GIS TUTORIAL 1 - Basic Workbook 44

Summary File (SF 1) tables GIS TUTORIAL 1 - Basic Workbook 45

Summary File (SF 3) tables GIS TUTORIAL 1 - Basic Workbook 46

SF tables comparisons SF 1 SF 3 § Population § Income § Age § Educational attainment § Sex § Citizenship § Race § Transportation § Housing units § Detailed housing § FFH GIS TUTORIAL 1 - Basic Workbook 47

Census summary u u u Shapefiles downloaded from www. census. gov or www. esri. com Data tables downloaded from American Factfinder http: //factfinder. census. gov Data joins needed to join SF 1 or SF 3 to shapefiles GIS TUTORIAL 1 - Basic Workbook 48

Lecture 5 VECTOR DATA FORMATS GIS TUTORIAL 1 - Basic Workbook 49

Arc. Info coverages u u Created using ESRI’s Arc. Info software Older format Set of files within a folder or directory called a workspace Files represent different types of topology or feature types GIS TUTORIAL 1 - Basic Workbook 50

Coverage attribute table u Area and perimeter § Coverage_ and Coverage_ID GIS TUTORIAL 1 - Basic Workbook 51

Shapefiles u Arc. View native format § Minimum files q shp–stores feature geometry q. shx–stores index of features q. dbf–stores attribute data § Additional files q. prj–projection data q. xml–metadata q. sbn and. sbx–store additional indices GIS TUTORIAL 1 - Basic Workbook 52

CAD drawings u CAD software § Autodesk, Auto. CAD (. dwg) § Bentley, Microstation (. dgn, . dxf) u Often used by engineering companies u Better digitizing precision GIS TUTORIAL 1 - Basic Workbook 53

CAD drawings GIS TUTORIAL 1 - Basic Workbook 54

CAD layers GIS TUTORIAL 1 - Basic Workbook 55

Event files Data table that includes map coordinates, such as latitude and longitude or projected coordinates GIS TUTORIAL 1 - Basic Workbook 56

Event files GIS TUTORIAL 1 - Basic Workbook 57

Export event files u Creates point features GIS TUTORIAL 1 - Basic Workbook 58

Lecture 5 RASTER DATA FORMATS GIS TUTORIAL 1 - Basic Workbook 59

Digital file formats u TIFF (Tagged Image File Format) § § u . tif file extension Very high quality images Commonly used in publishing Sizes are large because it is uncompressed GIF (Graphic Interchange Format): §. gif as its file extension. § Ideal for schematic drawings that have relatively large areas with solid color fill and few color variations. § Small file sizes GIS TUTORIAL 1 - Basic Workbook 60

Digital file formats u JPEG (Joint Photographic Experts Group): §. jpg file extension. § Most widely used format for photographs and other images that have a lot of color variations § Uses file compression at the expense of picture detail, if you specify a lot of compression GIS TUTORIAL 1 - Basic Workbook 61

Summary § Map projections § Coordinate systems § GIS data sources § Vector data formats § Raster data formats GIS TUTORIAL 1 - Basic Workbook 62