google earth pro fundamentals - amazon...
TRANSCRIPT
Data Visualization Techniques with Google Earth
E-Learning for the GIS Professional – Any Time, Any Place! geospatialtraining.com
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
Module Outline
• Navigation
• Creating Features
• Search
• Places and Layers Panel
• Understanding KML
• Overview of Google Earth Pro Features
4
Navigation
• Many ways to navigate
– User interface components
– Mouse
– Keyboard
• Can zoom, pan, tilt, change orientation, rotate
• Demonstration
5
Creating Placemarks
• Add Placemark tool
• Click a location on the GE display
• Can change
– Icon
– Style and color
– View
– Altitude
6
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
Creating Paths
• Add Path tool
• Draw two or more points and a path will automatically connect the points
• Automatically calculates distance of path
8
Creating Polygons
• Add Polygon tool
• Create a set of points that define the polygon
– Double click the last point to close the polygon
9
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
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
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
What is KML?
• 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
13
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)
http://www.opengeospatial.org/standards/kml
• Currently at KML version 2.2
– Continues to evolve under OGC
14
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
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
Data is Easy to Distribute
• All content contained within KML or KMZ file
• Can be distributed via
– Internet
– Network Server
– Web Services
17
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
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
Module Outline
• Address geocoding
• Adding all your properties to Google Earth using geocoding
• Adding properties manually as points
• Creating land parcels as polygons
21
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 = -98.4743, 29.6618
22
Geocoding Accuracy Levels
Rooftop
Street Segment
Geometric Center
Approximate
High Precision Fallback
23
Low Precision
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
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 100-200 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
25
Main St.
100 200 150
Longitude: -96.3462, Latitude: 20.4521
Geocoding in Google Earth Pro
• 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
26
Geocoding in Google Earth Pro
• Starts with a text file containing addresses
• Address components can be in separate columns or a single column
27
Geocoding in Google Earth Pro
• Other dialogs:
– Select latitude/longitude fields
– Address field information
– Specify field types
29
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
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
Exercise
• Please complete the following exercise:
Adding Addresses to Google Earth with Geocoding
33
Adding Features Manually
• Use the Add Placemark tool
• Click the location of the feature in GE
34
Demonstration
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
Custom Icons
• Can add your own custom icons
• Many available on the web
• Map icons collection
http://mapicons.nicolasmollet.com
• KML4Earth
http://kml4earth.appspot.com/icons.html
36
Perimeter and Area of a Polygon
• Measurements tab
• Automatically determines perimeter and area
• Can change units of measurement
– Feet, miles, meters, etc
38
Module Outline
• Styling your icons
• Introduction to info balloons
• Adding text, photos, video, links to info balloons
• Using templates to create info balloons
41
Styling Properties with Icons
• Placemarks can be styled with icons
– Google Earth provides many icons
– You can also supply your own
42
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
Adding Information to Info Balloons
• Add information to balloons by editing Placemark
– Select Placemark and then Get Info
• Description tab
44
Adding a Link to a PDF File to an Info Balloon
• Can also link to PDF and other file formats
• Use <a> HTML element
– Provide a URL to the file
46
Module Outline
• Demographic information
• Parcel information
• Traffic counts
• Importing GIS datasets
• Styling imported datasets
51
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
Exercise
• Please complete the following exercise:
Displaying Demographic Data in Google Earth Pro
54
Parcel Information
• Google Earth Pro dataset
• Parcel boundaries
• Parcel information
• Layers Earth Pro US Parcel Data
55
Traffic Counts
• Google Earth Pro dataset
• Layers Earth Pro US Daily Traffic Counts
• Lists traffic counts by year for that location
56
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
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
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
Adjusting the Transparency
• You may want to adjust the transparency of the map so that you can see the imagery
below
64
Exercise
• Please complete the following exercise:
Creating Thematic and 3D Maps with Google Earth Pro
66
Module Outline
• Emailing 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
Printing Maps
• Map options for printing
– Title and Description
– Legend
– Scale
– Compass
– HTML Area
– Styling
• Can save configuration file for
later use 70
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
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
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
Movie Maker
• Real-time interaction or tours
• Web site, presentation, email
• Windows Media Player
• Apple QuickTime
76
Module Outline
• Overview of adding images to Google Earth
• Add Image Overlay tool
• Defining coordinates for the image
78
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
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
Some Image Files are Georeferenced
• 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
84
Module Outline
• What is a Network Link?
• Network Link Concepts
• How Network Links Work
• Reasons for Using Network Links
87
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
Example.kml Example2.kml
KML loaded “in memory”
88
Network Link Overview
89
• 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
Network Link Overview
90
<NetworkLink>
Web Server
Script
GE as web client
KML returned as stream
Database
File
Web
Service
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
Network Link Examples
• Examples
– These links will open in Google Earth and periodically refresh
– Current North American Wildland Fires
http://firefly.geog.umd.edu/kml/download.php?file=USA_contiguous_and_Hawaii_24h.kml
Select Add --> Network Link in GE and paste this URL
in the Link textbox
USGS Earthquake Monitoring
http://earthquake.usgs.gov/eqcenter/recenteqsww/catalogs/eqs7day-age.kmz
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
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
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
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
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
Exercise
• Please complete the following exercise:
Defining a Viewshed for a Commercial Property
101
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
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