Data Visualization Techniques with Google Earth

Transcription

1 Data Visualization Techniques with Google Earth E-Learning for the GIS Professional Any Time, Any Place! geospatialtraining.com

2 Course Outline Module 1: Google Earth Pro Fundamentals Module 2: Adding Features to the Map Module 3: Attaching Information to Features Module 4: Adding Neighborhood Information Module 5: Creating Thematic and 3D Maps Module 6: Presentation and Communication Module 7: Adding Images to the Display Module 8: Sharing your Data Module 9: Terrain Information Module 10: Using Historical Imagery 2

3 GOOGLE EARTH PRO FUNDAMENTALS 3

4 Module Outline Navigation Creating Features Search Places and Layers Panel Understanding KML Overview of Google Earth Pro Features 4

5 Navigation Many ways to navigate User interface components Mouse Keyboard Can zoom, pan, tilt, change orientation, rotate Demonstration 5

6 Creating Placemarks Add Placemark tool Click a location on the GE display Can change Icon Style and color View Altitude 6

7 Extruding a Placemark May be times when you want the icon to hover above the property Known as tethering String (or tether) drawn between the Placemark and the physical location Use Altitude tab Set altitude and absolute Check Extend to ground 7

8 Creating Paths Add Path tool Draw two or more points and a path will automatically connect the points Automatically calculates distance of path 8

9 Creating Polygons Add Polygon tool Create a set of points that define the polygon Double click the last point to close the polygon 9

10 Search Panel Google Earth recognizes the following search types City, State City, Country Number, Street, City, State Zipcode or Postal Code Latitude, Longitude (Decimal Degrees) Latitude, Longitude (Degrees, Minutes, Seconds) Free form (Museums in New York City) 10

11 Places Panel Contains temporary datasets Temporary Places folder Only used for current GE session Removed when you close GE Datasets saved to your local computer My Places Persist between sessions Right click a layer from Temporary Places folder and select Save to My Places 11

12 Layers Panel Contains Google provided datasets Created by Google or its content partners Always available in GE Can t add your layers to the Layers panel 12

13 Keyhole Markup Language or KML XML grammar and file format for modeling and storing geographic features Tag based structure (XML) Similar to HTML Can be created in Google Earth, XML editors, or text editors (jedit, Notepad++) Can be shared What is KML? 13

14 Open GeoSpatial Consortium and KML KML originally created by a company called Keyhole for it s Earth Viewer Later acquired by Google KML specification now controlled by Open Geospatial Consortium (OGC) Currently at KML version 2.2 Continues to evolve under OGC 14

15 KML Functionality Specify icons and labels on the earth s surface Define unique views using camera positions Drape images over the terrain Specify feature appearance with styles Write HTML descriptions of features, including hyperlinks and embedded images Use folders for grouping features Fetch data from remote servers Much more! 15

16 Reach a Wide Audience Google Earth KML files can be distributed via the web Users download files from the Internet Users can find KML files using Google Search XML Sitemap notifies Google to crawl your geo content Can also use GeoRSS KML search results also returned in Google Earth KML files found when doing a search in Google Earth for California wildfires 16

17 Data is Easy to Distribute All content contained within KML or KMZ file Can be distributed via Internet Network Server Web Services 17

18 KML Files What does a KML file look like? Below is a small sub-set of a KML file that defines a map overlay (Ground Overlay). Notice that it looks very similar to HTML Tags ARE case-sensitive 18

19 KML vs KMZ KML files can get VERY large when dealing with large datasets This is due to the amount of text that it takes to describe GE features Need a way to compress these files to make them smaller KMZ files are the compressed versions of KML files KMZ files also used to distribute additional files referenced by a main KML file Images, icons, textures, models, HTML GE can read KML or KMZ files Can open KMZ files with tools such as WinZip 19

20 ADDING FEATURES TO THE MAP 20

21 Module Outline Address geocoding Adding all your properties to Google Earth using geocoding Adding properties manually as points Creating land parcels as polygons 21

22 What is Geocoding? Process of converting physical addresses into geographic coordinates Address can t be added to map without geographic coordinates Example: 1202 Sand Wedge, San Antonio, TX = ,

23 High Precision Rooftop Geocoding Accuracy Levels Fallback Street Segment Geometric Center Approximate Low Precision 23

24 Rooftop Geocoding Also called point-level geocoding Most accurate determination More accurate for long street segments, cul-de-sacs, or irregularly spaced addresses Assigns a geographic coordinate to the actual rooftop of an address 24

25 Street Segment Geocoding Assigns latitude/longitude coordinates based on know geocodes at the intersection of the block or street segment containing an address Uses a process of interpolation Example: If a block runs from Main Street, then 150 Main Street would be approximately halfway between 100 and 200 Main Street Most commonly used method at this time More accurate in urban areas Rural areas are less complete Longitude: , Latitude: Main St. 25

26 GE Pro can import a text file containing a batch set of addresses Text file is typically delimited by a comma or tab Supported countries United States, United Kingdom, Canada, France, Italy, Germany, Spain Each address converted into a Placemark Geocoding in Google Earth Pro 26

27 Geocoding in Google Earth Pro Starts with a text file containing addresses Address components can be in separate columns or a single column 27

28 Geocoding in Google Earth Pro Go to File Import Find the file and open Data Import Wizard 28

29 Geocoding in Google Earth Pro Other dialogs: Select latitude/longitude fields Address field information Specify field types 29

30 Some Addresses Won t Geocode Not all addresses will geocode PO Boxes, Apartments, Suite Numbers New Addresses Misspellings and typos Can repair addresses in Google Earth 30

31 Defining the Address Placemark Icon Can apply a style template to the features Can define Name Defines how the Placemark will be labeled Color Icon color Icon Style Height Clamp features to ground or set height from a field 31

32 Geocoding Results Addresses added as Placemarks Saved in a KML file 32

33 Exercise Please complete the following exercise: Adding Addresses to Google Earth with Geocoding 33

34 Adding Features Manually Use the Add Placemark tool Click the location of the feature in GE Demonstration 34

35 Styling the Feature Features can be styled by changing the icon Click the icon button to display list of icons Can also add your own custom icons Increase or decrease size of icon Use Scale property Default is 1.1 (higher number increases size) 35

36 Custom Icons Can add your own custom icons Many available on the web Map icons collection KML4Earth 36

37 Creating Polygons Demonstration 37

38 Perimeter and Area of a Polygon Measurements tab Automatically determines perimeter and area Can change units of measurement Feet, miles, meters, etc 38

39 Exercise Please complete the following exercise: Manually Creating Features with Google Earth 39

40 ADDING FEATURE INFORMATION 40

41 Module Outline Styling your icons Introduction to info balloons Adding text, photos, video, links to info balloons Using templates to create info balloons 41

42 Styling Properties with Icons Placemarks can be styled with icons Google Earth provides many icons You can also supply your own 42

43 Introduction to Balloons Balloons provide a way of communicating information about a place to your users Attached to Placemarks Can include Plain text, HTML, photos, video, links to files Excellent tool for presenting feature information to users Detailed information, photos, video, your logo 43

44 Add information to balloons by editing Placemark Select Placemark and then Get Info Description tab Adding Information to Info Balloons 44

45 The <a> HTML element used to add a link to the balloon Adding a Link to the Info Balloon 45

46 Can also link to PDF and other file formats Use <a> HTML element Provide a URL to the file Adding a Link to a PDF File to an Info Balloon 46

47 The <img> HTML element adds an image to the balloon Adding a Photo to an Info Balloon 47

48 Adding Video to an Info Balloon Use <iframe> HTML element to add video to an info balloon 48

49 Exercise Please complete the following exercise: Adding Feature Information to Info Balloons 49

50 ADDITIONAL DATASETS 50

51 Module Outline Demographic information Parcel information Traffic counts Importing GIS datasets Styling imported datasets 51

52 Demographic Information Google Earth Pro includes census demographic information Layers Earth Pro US Demographics Various Levels State County Census Tract Census Block Most current year (2011) Projections (2016) Age, education, gender, households, income, marital status, vehicle availability 52

53 Can also create a thematic map from any of the demographic variables Demographic Information 53

54 Exercise Please complete the following exercise: Displaying Demographic Data in Google Earth Pro 54

55 Parcel Information Google Earth Pro dataset Parcel boundaries Parcel information Layers Earth Pro US Parcel Data 55

56 Traffic Counts Google Earth Pro dataset Layers Earth Pro US Daily Traffic Counts Lists traffic counts by year for that location 56

57 Importing Other GIS Datasets Google Earth Pro can import GIS shapefiles (ESRI format) Shapefiles contain geographic locations and information about those locations Shapefile is actually several files with the same name and different file extension tracts.shp, tracts.dbf, tracts.shx, tracts.prj, and there may be others Many free sources of shapefiles on the Internet In GE Pro go to File Import Select the shapefile to be imported More than 2500 features can cause performance problems for GE 57

58 Styling the Imported Shapefile Style Template used to style imported records Name, Color, Icon, Height No icon if you re working with polyline or polygon data 58

59 Exercise Please complete the following exercise: Importing Shapefiles to Google Earth Pro 59

60 CREATING THEMATIC AND 3D MAPS 60

61 Module Outline Creating thematic maps Adjusting the transparency of a map Creating 3D maps 61

62 Creating Thematic Maps Example: Color code census tract boundaries by population Tracts with highest population represented by red Tracts with lowest population represented by white Everything in between will be a color shade variant Import a shapefile containing census tracts for Manhattan Borough Use Style Template to define colors for tracts Color code the tract boundaries based on POP2000 field Define buckets for color values 62

63 Creating a Thematic Map 63

64 Adjusting the Transparency You may want to adjust the transparency of the map so that you can see the imagery below 64

65 3D Display of Data Now let s add a third dimension to the data 65

66 Exercise Please complete the following exercise: Creating Thematic and 3D Maps with Google Earth Pro 66

67 PRESENTATION AND COMMUNICATION 67

68 Module Outline ing maps Printing maps Adding titles, legends, north arrows, and HTML to your printable maps Exporting maps as images or PDF files Creating tours and movies 68

69 ing Maps Use the button on the GE toolbar 69

70 Printing Maps Map options for printing Title and Description Legend Scale Compass HTML Area Styling Can save configuration file for later use 70

71 Printing Maps 71

72 Exercise Please complete the following exercise: Printing Maps with Google Earth Pro 72

73 Exporting Maps Can export Image files High resolution with Google Earth Pro (low resolution with free version of GE) Can set same Map Options as with Print PDF files Using Print toolbar 73

74 Creating Tours and Movies Can create tours and movies in Google Earth Fly from one place to another Add narration Show pop-up balloons Click Record a Tour button Tour recording tools displayed in lower left hand corner of viewport 74

75 Creating a Tour Create a tour of multiple Placemarks in a folder Right click Folder and select Add Tour All Placemarks in folder added to tour Click the Tour button to play 75

76 Movie Maker Real-time interaction or tours Web site, presentation, Windows Media Player Apple QuickTime 76

77 ADDING IMAGES TO THE DISPLAY 77

78 Module Outline Overview of adding images to Google Earth Add Image Overlay tool Defining coordinates for the image 78

79 Adding Images to the Google Earth Display Graphic files can be imported to GE as overlays Drape across the underlying terrain Image file formats include jpeg, bmp, gif, tiff, tga, and png You can also set a transparency on the image to see the underlying terrain. 79

80 Add Image Overlay Tool Use the Add Image Overlay tool Browse to an image file GE doesn t necessarily know where to place the image on the earth Need to know bounding coordinates of image OR Use the tools to center, rotate, and stretch the image 80

81 Add Image Overlay Dialog 81

82 Add Image Overlay - Location 82

83 Add Image Overlay - Location 83

84 Some image formats are already georeferenced GeoTIFF National Imagery Transmission Format (NTF) ERDAS Imagine Image (IMG) Can import these files without having to reposition Done automatically by GE Some Image Files are Georeferenced 84

85 Exercise Please complete the following exercise: Adding an Image Overlay to Google Earth 85

86 SHARING YOUR DATA WITH NETWORK LINKS 86

87 Module Outline What is a Network Link? Network Link Concepts How Network Links Work Reasons for Using Network Links 87

88 What is a Network Link? KML file that references another KML file on a local or remote network Google Earth fetches the referenced file into memory and loads the data to the display Often used to share data with others where the dataset changes frequently Monthly updates to commercial or residential real estate listings KML loaded in memory Example.kml Example2.kml 88

89 Network Link Overview Network Link contains the URL of another KML file Source file contains NetworkLink element that references and fetches data from another KML file or KMZ archive Fetched file can be local or remote Remote fetching comes from a web server Data can be updated remotely KML can be dynamically generated by a script 89

90 Network Link Overview GE as web client Web Service File <NetworkLink> Web Server Script KML returned as stream Database 90

91 Reasons for Using Network Links Frequent changes to data sets Data distributed over large area Need to update previously loaded data sets Partitioning of complex data sets

92 Examples Network Link Examples These links will open in Google Earth and periodically refresh Current North American Wildland Fires Select Add --> Network Link in GE and paste this URL in the Link textbox USGS Earthquake Monitoring

93 Scripting Network Links CGI scripting languages can be used to dynamically generate KML data streams to a Network Link Python Perl PHP Process Client (Google Earth) calls the server (KML or KMZ file) Server (KML or KMZ) file contains a pointer to the CGI script Server returns: Response code of HTTP 200 Sets the response content type to text/plain or application/vnd.google-earth.kml+xml Valid KML code This is powerful functionality for dynamically generating content Covered extensively in our Creating Real Time Google Earth Applications course. 93

94 TERRAIN INFORMATION 94

95 Module Outline Creating a viewshed Creating an elevation profile 95

96 Viewshed Basics GE Pro feature 360-degree view of area visible from a Placemark Doesn t limit the view to a particular angle Visible area highlighted in green; non-visible area shaded in gray 96

97 Viewshed Example 97

98 Viewshed Examples Architects can analyze the views available from a tract of land before designing buildings. Real estate agents can evaluate views remotely, and take views into consideration when they set property prices. Land developers can illustrate the viewable areas of parcels Businesses can make rough estimates of cell tower coverage from a particular location. Advertisers can try out different locations for billboards and signs. 98

99 How Viewshed Works Uses terrain layer to calculate Viewshed is calculated from Placemark view What you would see if you were at the Placemark itself, looking out at the view all around you This is the view that Viewshed calculates. Camera view View of the Placemark and its surroundings This is the view GE displays In other words, Earth Pro calculates the viewshed from the Placemark view and displays the viewshed from the Camera view. 99

100 Using Viewshed 1. Select an existing placemark or create a new one. 2. Right-click the placemark, then select Get Info. The Edit Placemark dialog appears. 3. Click Altitude and adjust the altitude so that it's at least approximately one meter above the surface, then click OK. 4. From either the Edit menu or the placemark s right-click menu, select Show Viewshed. 100

101 Exercise Please complete the following exercise: Defining a Viewshed for a Commercial Property 101

102 Elevation Profiles Explore elevations of a particular path Draw a new path or open an existing path Edit Show Elevation Profile Right click the path in Places panel and select Show Elevation Profile Y-axis displays elevation X-axis displays distance 102

103 Exercise Please complete the following exercise: Creating an Elevation Profile for a Path 103

104 USING HISTORICAL IMAGERY 104

105 Overview of Historical Imagery See how places have changed over time Some areas have imagery going back in time By default, GE displays the most recent imagery Click the Historical Imagery button to display the time slider Displays the oldest imagery available on left hand side of slider Small vertical lines indicate date when imagery is available Use tools provided to move back and forth in time 105

106 Overview of Historical Imagery Demonstration 106

107 1950 Historical Imagery Example Las Vegas

108 Historical Imagery Slider 108