gis tutorial 1 lecture 6 digitizing. outline  digitizing overview  gis features  digitizing...

Download GIS Tutorial 1 Lecture 6 Digitizing. Outline  Digitizing overview  GIS features  Digitizing features  Advanced digitizing tools  Spatial adjustments

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  • Slide 1
  • GIS Tutorial 1 Lecture 6 Digitizing
  • Slide 2
  • Outline Digitizing overview GIS features Digitizing features Advanced digitizing tools Spatial adjustments Digitizing sources 2 GIS TUTORIAL 1 - Basic Workbook
  • Slide 3
  • DIGITIZING OVERVIEW Lecture 6 3 GIS TUTORIAL 1 - Basic Workbook
  • Slide 4
  • Why digitize? New maps Map features are wrong Missing features Other? 4 GIS TUTORIAL 1 - Basic Workbook
  • Slide 5
  • Digitizing tablets Used to digitize hard copy maps into GIS Transform wire intersections into coordinates of the tablets coordinate system Heads down digitizing 5 GIS TUTORIAL 1 - Basic Workbook
  • Slide 6
  • Steps for heads down digitizing Tape map to the digitizer Register control points on the map Estimate two conversion equations (one for vertical and one for horizontal coordinates) Digitize vectors (points, lines, or polygons) 6 GIS TUTORIAL 1 - Basic Workbook 6 Control points Map Puck Tape
  • Slide 7
  • Heads up digitizing Mouse on a screen Digitizes paper maps, aerial photos, or other images GIS TUTORIAL 1 - Basic Workbook 77
  • Slide 8
  • GIS FEATURES Lecture 6 8 GIS TUTORIAL 1 - Basic Workbook
  • Slide 9
  • Points Single features Nodes Line endpoints Vertex points Controls shapes of lines and polygons 9 GIS TUTORIAL 1 - Basic Workbook
  • Slide 10
  • Creating points Heads up digitizing Single point features Sketch tool and snapping features Points added as XY event files Points geocoded using addresses 10 GIS TUTORIAL 1 - Basic Workbook
  • Slide 11
  • Lines Starting and ending points with shape vertices as needed Vertex points 11 GIS TUTORIAL 1 - Basic Workbook
  • Slide 12
  • Lines Physical attributes of TIGER streets Shape From and To attributes Node Address Lat/long Length GIS TUTORIAL 1 - Basic Workbook 12
  • Slide 13
  • Polygons Three or more lines joined to form a closed area Single polygons or multipart features (Hawaiian islands can be multiple polygons as one feature) 13 GIS TUTORIAL 1 - Basic Workbook 0 0 1 2 4 3
  • Slide 14
  • Polygons Physical attributes Shape Area Perimeter Length 14 GIS TUTORIAL 1 - Basic Workbook
  • Slide 15
  • DIGITIZING FEATURES Lecture 6 15 GIS TUTORIAL 1 - Basic Workbook
  • Slide 16
  • Create new feature class Created in ArcCatalog 16 GIS TUTORIAL 1 - Basic Workbook
  • Slide 17
  • Create new feature class Add spatial reference information 17 GIS TUTORIAL 1 - Basic Workbook
  • Slide 18
  • Create new feature class Add new fields GIS TUTORIAL 1 - Basic Workbook 18
  • Slide 19
  • Create new feature class Feature class created 19 GIS TUTORIAL 1 - Basic Workbook
  • Slide 20
  • Creating Feature Layers or Shapefiles in ArcMap 20 GIS TUTORIAL 1 - Basic Workbook Within ArcMap: -Locate an existing data layer that is similar to the layer that you wish to create. -Start editing the existing layer, then digitize the new feature -Select the new feature -Export the selection to a shapefile -Add the shapefile- fields already present and map projection is already defined -Examples in the instructor exercise
  • Slide 21
  • Digitize new features Create base map Add feature in ArcMap Start editing (Editor toolbar) Digitize feature Stop editing and save 21 GIS TUTORIAL 1 - Basic Workbook
  • Slide 22
  • Create base map for digitizing Vector features or raster images 22 GIS TUTORIAL 1 - Basic Workbook
  • Slide 23
  • Add new feature class 23 GIS TUTORIAL 1 - Basic Workbook
  • Slide 24
  • Add Editor toolbar Customize, Toolbars, Editor toolbar 24 GIS TUTORIAL 1 - Basic Workbook
  • Slide 25
  • Start editing Editor, Start editing 25 GIS TUTORIAL 1 - Basic Workbook
  • Slide 26
  • Begin digitizing 26 GIS TUTORIAL 1 - Basic Workbook
  • Slide 27
  • Click point (tree) locations 27 GIS TUTORIAL 1 - Basic Workbook
  • Slide 28
  • Stop editing Editor, Stop editing 28 GIS TUTORIAL 1 - Basic Workbook
  • Slide 29
  • Edit attribute data Start editing, populate fields in table 29 GIS TUTORIAL 1 - Basic Workbook 12
  • Slide 30
  • ADVANCED DIGITIZING TOOLS Lecture 6 30 GIS TUTORIAL 1 - Basic Workbook
  • Slide 31
  • Specify angle and length Lines and polygons Straight segment tool Type length and angle 31 GIS TUTORIAL 1 - Basic Workbook
  • Slide 32
  • Snapping tools Snapping toolbar 32 GIS TUTORIAL 1 - Basic Workbook Point Snapping Endpoint Snapping Vertex Snapping Edge Snapping
  • Slide 33
  • Trace tool Good for complicated shapes Editor toolbar, Trace tool 33 GIS TUTORIAL 1 - Basic Workbook
  • Slide 34
  • Generalize tool Creates features for use at small scales with less detail while preserving basic shapes U.S. Census cartographic boundary files 34 GIS TUTORIAL 1 - Basic Workbook Census TIGER water featureCity planning rivers
  • Slide 35
  • Smooth tool Smoothes sharp angles in polygon outlines to improve aesthetic or cartographic quality 35 GIS TUTORIAL 1 - Basic Workbook Smooth before Smooth after
  • Slide 36
  • Cut polygons Creates two polygons from one original Cut polygon tool GIS TUTORIAL 1 - Basic Workbook Polygon beforePolygon after 36
  • Slide 37
  • SPATIAL ADJUSTMENTS Lecture 6 37 GIS TUTORIAL 1 - Basic Workbook
  • Slide 38
  • Transforms Converts data from one coordinate system to another. from digitizer or scanner units to real world coordinates. Shifts data within a coordinate system, (e.g. feet to meters). 38 GIS TUTORIAL 1 - Basic Workbook
  • Slide 39
  • Rubbersheeting Geometric distortions commonly occur in source maps may be introduced by imperfect registration in map compilation lack of geodetic control in source data variety of other causes Corrects flaws through the geometric adjustment of coordinates GIS TUTORIAL 1 - Basic Workbook 39
  • Slide 40
  • Edgematching Aligns features along the edge of one layer to features of an adjoining layer Layer with the less accurate features is adjusted, while the adjoining layer is used as the control. Attribute transfer is typically used to copy attributes from a less accurate layer to a more accurate one. 40 GIS TUTORIAL 1 - Basic Workbook
  • Slide 41
  • Spatial adjustment example Hamburg Hall CAD Drawing CAD drawings generally do not have geographic coordinates 41 GIS TUTORIAL 1 - Basic Workbook
  • Slide 42
  • Spatial adjustment example Spatially match drawing to map using displacement links GIS TUTORIAL 1 - Basic Workbook 42
  • Slide 43
  • DIGITIZING SOURCES Lecture 6 43 GIS TUTORIAL 1 - Basic Workbook
  • Slide 44
  • USGS United States Geological Survey Common Data Types & Standards Digital Elevation Models (DEMs) Digital Orthophoto Quads(DOQQs) Digital Line Graphs(DLGs) Digital Raster Graphics (DRGs) Landsat Satellite Images Land Use Land Cover (LULC) Spatial Data Transfer Standard(SDTS) 44 GIS TUTORIAL 1 - Basic Workbook
  • Slide 45
  • Orthophotography Digital imagery in which distortion from the camera angle and topography have been removed, thus equalizing the distances represented on the image 45 GIS TUTORIAL 1 - Basic Workbook
  • Slide 46
  • Digital Ortho Quarter QuadsDOQQs http://online.wr.usgs.gov/ngpo/doq/ Grayscale or color-infrared (CIR) images 1-meter ground resolution; Cover an area measuring 3.75 minutes longitude by 3.75 minutes latitude, approximately 5 miles on each side Referenced to the North American Datum of 1983 (NAD83) and cast on the Universal Transverse Mercator (UTM) projection 46 GIS TUTORIAL 1 - Basic Workbook
  • Slide 47
  • DOQQ image resolutions The ground length of one pixel of the image image with one meter resolution means that each pixel in the image represents one square meter on the ground. 30 meters 10 meters 5 meters 47 GIS TUTORIAL 1 - Basic Workbook
  • Slide 48
  • DOQQ image resolutions 2 meters 1 meter 48 GIS TUTORIAL 1 - Basic Workbook
  • Slide 49
  • National Elevation Data Sets United States Geological Survey (USGS) National Elevation Dataset (NED) Shaded Relief Imagery Data (Free) Maps provide highest-resolution elevation data available across the United States, in raster format http://ned.usgs.gov/ http://ned.usgs.gov/ 49 GIS TUTORIAL 1 - Basic Workbook
  • Slide 50
  • Scanning paper documents Raster to vector conversion Paper (historic) maps Scanned maps and images become vectors Special software needed 50 GIS TUTORIAL 1 - Basic Workbook
  • Slide 51
  • Summary Digitizing overview GIS features Digitizing features Advanced digitizing tools Spatial adjustments Digitizing sources 51 GIS TUTORIAL 1 - Basic Workbook