Applications DANA PORTER LIBRARY February 19, 2013 Authored by: The Geospatial Centre 0
TABLE OF CONTENTS Google Earth Introduction... 2 Historical Imagery... 3 Objective... 3 Step by Step... 3 Ruler... 4 Objective... 4 Step by Step... 4 Directions... 5 Objective... 5 Step by Step... 5 Creating a Placemark... 7 Objective... 7 Step by Step... 7 Layers... 9 Objective... 9 Step by Step... 9 Routes/Elevation... 9 Objective... 9 Step by Step... 10 Placing a Map Spatially... 12 Objective... 12 Step by Step... 12 Creating a Narrated Animated Tour... 15 Objective... 15 Step by Step... 15 Appendix I: Adding a Legend in Google Earth... 19 Objective... 19 Step by Step... 19 Appendix II: Customizing the Placemark Message Window... 21 1
GOOGLE EARTH INTRODUCTION Google Earth is a free, powerful yet simple tool for viewing information spatially, whether it is viewing climate information, analysing change over time, reviewing sites seen or remembering routes taken while on your latest holiday. Google Earth can do all of these things and still integrate with powerful GIS tools if or when advanced analysis is needed. In this tutorial you will learn how to create placemarks (points of interest), analyse elevation changes over the landscape, import images, georeference maps/photos, utilize the built in library (3D buildings, weather, photo gallery, etc.), view historical imagery, navigate to a city with the directions module, and create a route. Figure 1 The sidebar on the left hand side of the screen holds a few different modules. On the top is the search module which can be used to search for locations using various methods, such as latitude/ longitude, cities, provinces/states, nations, administrative boundaries, addresses or most other types of spatial divisions used in the area. The middle module is called Places and is where we can manage the information we save in Google Earth. 2
The final module contains a variety of information created by the Google Earth community. Some examples of information included in this module are images, weather, labels, 3d buildings and much more. The toolbar at the top of the Google Earth interface gives access to a variety of features provided within Google Earth. Many of these are explained below including placemarks, image overlays, historical imagery, etc. There is more helpful information at the bottom of the screen. The latitude and longitude of your current cursor location is displayed at the bottom centre of the window. Directly to the right of the latitude and longitude is the current elevation of the current cursor location. Finally the value on the far left of the screen represents the Eye altitude or the altitude that Google Earth is currently viewing the world from. HISTORICAL IMAGERY Historical Imagery can be a very useful tool when utilized in the right circumstance. It enables the user to analyse change in the landscape overtime. For example we can use the historical imagery to document the landscape changes from the tsunami that struck Japan in 2010. OBJECTIVE Find Ichibanyama Arahama, Japan and notice the changes in the landscape before and after the tsunami using the Historic Imagery function in Google Earth. STEP BY STEP In the search text box in the upper left-hand corner, enter Ichibanyama Arahama and click Search Figure 2 After viewing the area select the Show historical imagery button in the upper middle area of the screen just above the map as seen in Figure 2. 3
A scroll bar will appear on the top left of your screen in the map window. Use it to scroll through imagery from different dates. You can see the before and after imagery from the Tohoku Earthquake. Feel free to examine other areas of interest to see what imagery is available and how much the land has changed. RULER OBJECTIVE Use the ruler to find the shortest route for a trip you make fairly commonly. STEP BY STEP Select the Ruler tool from the toolbar Figure 3 After the ruler button is selected a new window will appear. This window contains options pertaining to the ruler. There are two tabs in this window, the Line and Path tab. Figure 4 When the Line tab is selected, a left click will place the starting point of the ruler and the second left click will place the end point. The distance will be shown in the Ruler window. The ruler can be moved by either clicking to start a new start point or by dragging the ruler points. The line ruler has some limitation however as it can only create a single straight line. If a measurement requires any change in direction the Line tool will have to be recreated and calculated manually. 4
The Path Ruler however can do this automatically. The Path Ruler can be accessed by clicking the Path tab in the ruler menu. The Path Ruler can be used to measure objects that change in direction such as roads or pathways. Left clicking will create a starting point and then each subsequent left click will create another point that the ruler will wrap around. Right clicking will delete the last point created. The left mouse button can be held down to activate freehand drawing mode which can be used to create curves or other shape of that nature. Double left clicking when creating the last desired point will stop the path creating process and the resultant distance will appear in the Ruler menu. DIRECTIONS The direction tool can be used to quickly and efficiently navigate to a position. GPS navigation units can do this as well, however Google Earth can do more. Google Earth allows the user to navigate public transit systems and optimize your route based on a few factors. OBJECTIVE Use the directions module to find the quickest route to your closest shopping mall or place of interest. STEP BY STEP Use Directions tab to easily navigate through transit systems. Click on the Get Directions button located at the top left of your screen as shown in Figure 5. Figure 5 5
Two text boxes will appear as seen in Figure 6. Insert your starting location in A and destination in B and select the Get Directions button to continue. Figure 6 After selecting the Get Directions button, Google Earth will plot a route to your location by vehicle. However you can use the options depicted in Figure 7 to use various other types of transport. Select the second button from the left as show in Figure 7 which represents public transit. Figure 7 Google Earth will plot several routes to your destination using the various public transit systems in the area. It will also show how long the trip will take and at what time you should leave to arrive at the bus stop on time. 6
CREATING A PLACEMARK Placemarks are one of the simplest yet most versatile tools in Google Earth. In their simplest form they are used to denote a specific location geographically. They can also contain information about this point. For example they can be used to show where a Hotel is located. The name of the placemark could be Hotel and its address, accommodations, continental breakfast hours, video tour, floor plan, etc. This information can be displayed when the placemark is selected. OBJECTIVE View the rainforest on Mount Mabu, Mozambique and create a placemark to represent it. Next search for the shipwreck at 19.646407, 37.294938 and create a placemark for it as well. STEP BY STEP Placemarks have a variety of uses in Google Earth but essentially represent Points of Interest you can refer back to after. To start, enter Mount Mabu, Mozambique into the search box at the top left of your screen. Figure 8 Next, select the placemark button in the toolbar as seen in Figure 8. After selecting the placemark a new window will open. This window is where the various properties of the placemark can be modified. Enter your desired name for the placemark in the Name field and leave the rest as their defaults. Figure 9 7
Leave the window open and then drag the yellow pin on the map onto the peak of Mount Mabu before selecting Okay. When the window is open the placemark can be moved but not while it is closed. If the name or other options need to be modified, right click the placemark on the left side of your screen under the region labeled Places. After right clicking, select the properties option. The properties pane will open and changes can be made. The placemark can also be dragged into different folders in the places tab. To create a new folder right click in white space away from any of the folders and files. Navigate to new -> folder. It is very important that we include all of our points in the same folder when we want to share them. This placemark can also be saved onto your computer. Right click on the placemark and select save place as. To include multiple placemarks in the same file you need to create a folder. Right click on the folder and select save place as to save the entire folder as one file. These files we have saved are called kmz files and can be opened by anyone who has Google Earth installed on their computer. In the properties pane the placemark icon (the yellow pin) can be modified by clicking on the pin button at the top left of the pane. This will bring up a variety of icons, simply select one and press ok to apply the icon to the point. In the description tab of the placemark addition information can be added. This information will only be displayed after the placemark is clicked on. An image can be added by selecting the add image button and navigating to the image or pasting a URL. Text can also be typed in the text box below the add image button. Figure 10 8
LAYERS Google Earth contains information other than just satellite imagery. Google and various organizations and users have created variety of other useful datasets. These include 3D buildings, panoramic photos, weather or even earthquakes. OBJECTIVE Navigate to Rome, Italy and explore the different layers especially the 360Cities and 3D Buildings layers. STEP BY STEP Type Rome, Italy into the search bar. Review the layers tab of the sidebar located on the bottom left of the screen. Next click the checkbox to the left of the 3D Buildings options. Now zoom in and the 3d models of many of the buildings can be seen. All of the models may not be displayed instantly as they will load slowly. By holding your middle mouse button down or by selecting the up arrow located at the top right of the screen. This modifies the pivot or viewing angle which makes it easier to view 3d datasets. Take a few minutes too look around at all the different models. The 3d buildings layer allows the user to experience the imagery with an added level of immersion. This experience can be enhanced using some of the other layers available. Next select the arrow beside the Gallery category, more layers will appear. Select 360Cities from this list. A bunch of red bubbles that contain the text 360 will appear if Google Earth is zoomed to the right scale. If they are not displayed zoom to a level where the majority of Rome is visible and they will appear. Next click a bubble and select View this image on 360 Cities. A panoramic photo will appear. The photo can be navigated by holding down the left mouse button and moving the mouse in the direction the user wants to view. At the top left of the screen there is a Back to Google Earth button to return to Google Earth. Take some time and explore the various images. There are a variety of other layers that can be explored in a similar fashion. Browse through the layers and try some others out. ROUTES/ELEVATION Similar to the ruler tool above the route tool allows the user to draw a route (path) and then access information about that path. In this example we will be exploring the elevation changes along a path in an area with very drastic elevation changes. OBJECTIVE Navigate to Mount Everest and create a path from a nearby settlement to the mountains peak. Investigate the elevation change using the elevation profile. 9
STEP BY STEP In order to show how the route and elevation tools work, type Mount Everest into the search bar. From here select the route button on the toolbar as shown below. It is the third button from the left. Figure 11 After selecting the button the path / route property will appear as shown below. Figure 12 As long as this pane is open you can draw a path into Google Earth but if this pane is closed you can no longer edit the path (can add similar information from this pane as what was added during the placemark section). 10
As you are drawing your route notice that left click will add a point while right click will delete a point. Also note that if you hold down your left mouse button you can draw freehand. Draw a path up the mountain. When you are done drawing your path, click the OK button on the properties pane (the pane shown above). On the left hand side of your screen the path will be shown in My Places as seen in the Figure below. Right click on the path and select Show Elevation Profile. A new interface will now be displayed at the bottom of your screen. This pane allows access to a few types of information including elevation at any particular point and distance from origin. As the cursor is moved along the graph the point corresponding to the location on the x access will be displayed on Google Earth spatially. Note: Holding the middle mouse button down while moving your mouse will also change the view angle which will make elevation differences easier to view. Figure 13 11
PLACING A MAP SPATIALLY Google Earth also supports adding images directly onto the aerial imagery. This differs from adding photos with placemarks (see Placemarks section) as the placemarks are just one point and so are useful for placing a picture. This process is called geocoding. However they are not useful when trying to compare changes to the terrain over time from historical imagery. In the latter case we will need to place the map spatially otherwise known as georeferencing the imagery. OBJECTIVE Georeference a map of the University of Waterloo Campus taken from the internet. STEP BY STEP Taking a paper map and converting it into digital form can be handy. With the digital copy a variety of techniques can be used to place the map spatially which has a variety of uses. Google Earth has this function. This technique is called georeferencing. First type in University of Waterloo, Waterloo, ON into the search box and then move the view extent until Ring Road is clearly in view. Ring Road is shown below. Figure 14 12
Now select the image overlay button in the toolbar at the top of the screen and also shown in the screenshot below. Figure 15 After selecting this button a new window will be displayed called the Properties Pane. The Properties Pane can be used to edit almost everything about this particular feature (Image Overlay). This feature can be named in the same fashion as placemarks or paths but has an additional textbox below it named Link: This textbox will be used to tell Google Earth where the image is that you would like to georeference. Images can be used directly from the internet by pasting the URL into this box or the browse button can be used to navigate to an image on your computer. For this tutorial we will be using the image from the URL: (http://www.math.uwaterloo.ca/~bguenin/images/campusmap.jpg). Insert this URL into the link textbox or download the image and browse to its location on your computer. Selecting OK at this point will display the image at the current extent of your window. Since the image will be placed in your current screen extent it can be helpful to first navigate to approximately the image s correct position to avoid further hassle later on. Figure 16 13
The image overlay will also now pop up on the left side of your screen under My Place, the same way the rest of the features have. The Properties Pane can be found again by right clicking the image overlay in this interface and selecting Properties. When the properties pane is reopened it unlocks a variety of options for moving the image. With the Properties Pane open there will be green lines along the edges, corners, and middle of the image which can be used to drag the image around to its correct position. The image can be rotated by going to the Location tab in the Properties Pane and modifying the Rotation: field. The Convert LatLonQuad button on this tab will allow the image to be placed using coordinates for each corner of the map if that is easier to perform. See Figure 17 for the locations of each option. Figure 17 After the image is positioned properly select ok. Congratulation you have successfully georeferenced an image. The georeferenced image that was just created can be saved by right clicking on the image overlay that corresponds with the image file on the left hand side of the screen, right clicking and selecting Save Place As. This image can be shared with others. Warning: Make sure that the points you want to share are in a folder and you right click the folder and not the individual file. The file that is created is called a kmz file because its file extension is.kmz. These files interact slightly differently depending on whether the image was linked locally or via the internet. This is further discussed below in Self-Contained KMZ Files. 14
CREATING A NARRATED ANIMATED TOUR You can create a tour that records your exact navigation in the 3D environment and add an audio commentary using a drawn route. OBJECTIVE The objective is to guide you through recording and playing a tour where you fly from one location to another along a route, and explore the locations with Photos, 360-degree Google Street View and 3D buildings. You will be creating a tour of the Forbidden City in Beijing, China. Formatte color: Auto Formatte color: Auto STEP BY STEP Before creating the tour, you will create placemarks of the following locations: Tiananmen Square (39 54'26.10"N, 116 23'28.28"E) Wenhua Palace (39 54'49.26"N, 116 23'34.91"E) Main Halls of the Forbidden City in Beijing (39 54'56.21"N, 116 23'27.03"E) Wuying Palace Buildings (39 54'48.32"N, 116 23'17.74"E) You will begin your tour at the Tiananmen Square placemark. Using the Route Tool, draw the following tour paths: Tiananmen Square to Wenhua Palace, Wenhua Palace to Main Halls, Main Halls to Wuying Palace, and Wuying Palace to Main Halls. Under the Layer panel, turn on the Photos and 3D Buildings layers (Figure 18). Then Click the Add Tour button in the toolbar, or go to the Add menu and select Tour. The tour recording tools appear in the lower-left corner of the window (Figure 19). Figure 19 Figure 18 15
Click the Record button to start recording your actions and movements in Google Earth. The button changes to red and the time counter begins counting up, showing the duration of your current Tour. You will notice there are 3D buildings for the placemarks you have set up in the 3D viewer (Figure 20). Use the Navigation Controls in the top left corner and your mouse to move, tilt, rotate the globe and zoom in around the 3D building (Figure 21). Figure 20 Figure 21 There are some photo icons surrounding Tiananmen Square. Click one and a pop- up window showing the photo and its description appears (Figure 22). Figure 23 Figure 22 Once the 360 degree view of the Tiananmen Square is finished, you can press the stop recording button. Tour Player appears in the bottom-left corner of the 3D viewer (Figure 23). You can play the tour after the recording is done. To save the tour, click the Save to File button in the Tour Player, and give it a name. The new KML file will be saved in My Places. You can place all of your placemarks and the tour into a single folder called My Tour. Formatte color: Auto 16
You can modify and extend a previous tour by re-recording a new tour while playing back the original tour. The new tour will add a new action to move around the route you created earlier. You will add the Tiananmen Square to Wenhua Palace route to the 360 degree view of the Tiananmen Square by playing the recorded tour, followed by playing the route. Once this is complete, you will create a 360 degree Google Street view around Wenhua Palace to be added onto your tour. Formatte Formatte To add a new action into the existing tour, click the Add Tour button in the toolbar. The Record Tour Controls appear on the top of the Tour Player in the lower-left corner (Figure 24). Figure 22 Figure 23 Next click the Record button to start recording a new tour, then play the tour that you just created. Wait until the original tour finishes playing back. Since you are still recording, you can continue to add new actions. Click the TS to Wenhua route file in the My Places Panel and then click Play Tour button as seen in Figure 25. This allows you to add a tour along a route. Next click the Wenhua Palace placemark in the My Place panel and switch to Google Street View mode. On the Navigation Controls in the top left corner (Figure 21), find the Pegman icon and drag it to the middle of the building area (Figure 26). Then use your mouse to generate a 360 degree street level view. Repeat these steps with the remaining placemarks and routes. Figure 24 Once this is done, you can press the stop recording button and click the Save to File button in the Tour Player, and give the new tour a name (e.g. walking tour new). 17
You can now add an audio recording. Adding an audio in this way is easy but the quality of the commentary can be improved if you prepare a script in advance. You must have a microphone linked to your computer. Play the tour recording again to figure out how long each segment of the tour takes. A segment could be a 360 degree view of the Tiananmen Square. Write a script exactly for what you will say in the time that each segment takes, for instance now we walk around the Tiananmen Square Test your comments to see they fit the time slot. Re-record a tour, but this time you click the microphone button instead of the record button. The recording will start and Google Earth will capture audio from your computer's microphone. You can also turn on/off audio recording by clicking the microphone button again. When you're happy, click the Save button in the Record Tour Controls to save the tour. Audio recorded through your microphone is captured as an.mp3 file when you save the entire folder under My Places as a KMZ file. 18
APPENDIX I: ADDING A LEGEND IN GOOGLE EARTH OBJECTIVE You will learn how to add a legend/logo on the Google Earth s screen by creating an image file and a simple screen overlay KML file. STEP BY STEP First you will need to find a computer program which can be used to create drawings on a blank drawing area or on existing images (e.g. Microsoft Paint). Once completed, you will save the image file as either JPEG or PNG format to your computer. The image file size should be relatively small (Figure 25). Figure 25 Next you will need to create a simple screen overlay KML file as shown below. <?xml version="1.0" encoding="utf-8"?> <kml xmlns="http://www.opengis.net/kml/2.2"> <ScreenOverlay> <name>absolute Positioning: Top left</name> <visibility>1</visibility> <Icon> <href>http://kml-samples.googlecode.com/svn/trunk/resources/top_left.jpg</href> </Icon> <overlayxy x="0" y="1" xunits="fraction" yunits="fraction"/> <screenxy x="0" y="1" xunits="fraction" yunits="fraction"/> <rotationxy x="0" y="0" xunits="fraction" yunits="fraction"/> <size x="0" y="0" xunits="fraction" yunits="fraction"/> </ScreenOverlay> </kml> This placemark KML file contains the following key elements: <name> this is used as the label for the Placemark <Icon> icon that appears in the screen overlay overlayxy and screenxy controls the location of the legend on the screen Size specifies the size of the image for the screen overlay 19
Fortunately you don t have to type all the KML codes because Google provides an excellent website (KML Interactive Sampler) with a lot of useful KML code examples. The link to the website is given below: http://kml-samples.googlecode.com/svn/trunk/interactive/index.html# (This website requires the Google Earth Plug-in), or Google Google Earth Interactive KML Example. Browse the website to find the Absolute TopLeft screen overlay example from the website (Figure 26). Figure 26 Next copy and paste the KML code to a text editor (e.g. Microsoft Notepad, TextPad), change the code after <href> to the address where the legend is located on your computer (Figure 27). Figure 27 Once the code has been modified, you can save the text file as legend.kml (Figure 12). Open this file in Google Earth and you will notice a legend is added in the top left corner. Figure 28 If you would like to have more control on the size and location of the legend, please visit this webpage (https://developers.google.com/kml/documentation/kmlreference#screenoverlay). 20
APPENDIX II: CUSTOMIZING THE PLACEMARK MESSAGE WINDOW With basic html code knowledge, you can customize how the text or photo displays in the message window by creating some html tags. An html tag is a command used to change how the description looks. It will be surrounded in < and > with short form command in the middle. For example <b> is called a bold tab and is used to make the text bold. Most tags require an accompanying end tag, for instance </b>. You can use the following tags in description tab to customize the message window: 1. Bold tab <b> </b> Any text written in between the <b> and </b> will be bolded. Figure 29 2. Break tag <br> add a new line (a space or carriage return) in between your image and text Figure 30 21
3. Table tag <table> <table/> create a table The <tr> tag indicates a table row and <td> indicates a table cell. For each set of <tr> </tr> there will be one row in the table For each <td> </td> inside of a <tr> </tr> (row) there will be another column in that row. <table border="4" cellpadding="2" cellspacing="2" width="80%"> <tr> <td>column 1</td> <td>column 2</td> </tr> </table> Figure 31 4. <img> tag display an image When you add an image into the placemark using the procedure described in the assignment one, an image tag has been added. If you want to modify image dimensions, you may add a statement (e.g. width = 200 height 200 inside the tag. For more information on html code, please visit: http://www.web-source.net/html_codes_chart.htm#image. However, you may also with to work with the KML Interactive Sampler to achieve similar results. 22