GEOG 101: How To Use Google Earth Pro

Transcription

1 GEOG 101: How To Use Google Earth Pro Topographic maps have long been a tool for the geographer. As technology has progressed, new tools have become available to us that allow us to spatially analyze our surroundings much more accurately. Undoubtedly, I imagine everyone has heard of or used Google Maps. I also imagine that most everyone has heard of Google Earth and has had some level of exposure to it. Recently, Google Earth Pro because free to download to the public. Google Earth Pro allows us to conduct even more analysis and is a much stronger program than the regular Google Earth. This guide will walk you through the necessary steps to find, download, and utilize Google Earth Pro. STARTING OUT To start out, load the following link: The link will bring you to a page like the one below. Make sure that the following two boxes in the bottom left are selected: Latest version (7.1) Allow Google Earth to automatically recommend updates. Once you download the software, follow the steps to properly install it. Once you are prompted for a license key you will need to enter your and the license key GEPFREE. That code will authorize you to download the Pro version of the software.

2 AFTER INSTALLATION After you have installed Google Earth Pro it will be time to open it. Upon opening it you will have a screen resembling the image below. First we are going to need to make some quick changes to the properties so that we are all on the same page. For Mac Users: Click on Google Earth Pro in the drop down menu in the top left corner of the screen and select Properties (View image to the right). For Windows Users: Click on Tools from the dropdown menu in the top left corner of the screen and select Options (View image to the right).

3 After you have click Properties or Tools you will be brought to a menu that will look like the image to the right. This menu is exactly the same for both Mac and Windows users. The first setting you will need to change is under the 3D View tab. Under Show Lat/Long select Decimal Degrees. This can be seen in the red box and Decimal Degrees will be our preferred method of expressing coordinates of latitude and longitude. Underneath the box for Show Lat/Long is a checkbox for for Use high quality terrain (disable for quicker resolution and faster rendering. Feel free to select this is your computer is capable. If your computer cannot handle the high resolution terrain, it will take longer to create, though it will NOT affect your work. Next, move to the Navigation tab and go to the box titled Navigation. Select Do not automatically tilt while zooming. The default option can lead to some clunky measuring and will make it more difficult for you to place your points correctly. Instead, we will be measuring from directly overhead and do NOT want to tilt our image. Next, select Apply from the bottom of the menu screen and then OK to close out of the screen. Finally, we will click on View from the dropdown menu at the top of the screen and turn on Overview Map and Scale Legend.

4 NAVIGATING THE MAIN WINDOW First off, navigating around the map is done by clicking and dragging your cursor within the map screen. Zooming is done by scrolling in and out with your mouse/trackpad, or by selecting the (+) or (-) on the right side of the screen, found under the Compass. If you need to reset your direction to north, click on the N, found in the top-right corner of the screen. We will first look at the black box in the top right of the screen. Feel free to sign into your Google Account if you would like. Next, look in the bottom right corner. Here we find the Overview Map, along with information detailing the date of the visible satellite imagery, the latitude and longitude coordinates, the elevation of your cursor, and the elevation at which you are above the surface (view below).

5 Next, we would like to look at the light blue box in the bottom left. This is the Layers box. Look at the image to the right. Please make sure that the Primary Database, Borders and Labels, Roads, and Terrain boxes are selected and that all other boxes are turned off. Feel free to explore some of the other options. Under Ocean you can turn on boxes to let you see shipwrecks, track marine life, and peer under the surface of the ocean. Under Gallery you can check out Volcanoes, look at National Geographic information, and learn about earthquakes. We will not be using these in our exercises, but they can be very interesting to learn about on your own time. Next, we will look at the Search box and the Places box. The Search box allows you to input named landscape features (such as streams, volcanoes, etc), addresses, or latitude/longitude. In the exercise, you will be provided with a latitude and longitude value that you will input into the search bar. These values will appear like this: [ , ]. You will need to make sure you enter those exact coordinates or you will not be taken to the correct location. The Places box is where you will find the placemearks, lines, and polygons that you will have created during your analyses. We will touch on this more later. Finally, if you look at the yellow box, you will find the location of the scale bar. This will change as you zoom in or out.

6 The green box, above, is where you will go to find all the tools you will be using for your exercises. The first tool, looks like this: This is the Add Placemark tool. This tool allows you to place points at exact latitude and longitude points. When you select that tool a menu will open up (view image to right). This menu allows you to change the name of the placemark and enter exact latitude and longitude points. When you are provided with these points in the exercise they will allows be listed as [ Latitude, Longitude ], for example [ , ]. Once you have entered the correct information, click OK and your point will be placed. You do not need to worry about the rest of the tabs on this menu, as we will not be using them. The other necessary tool from the green box will look like this: This is the Ruler tool. When selected, a menu like the image shown to the right will appear. In this menu, make sure that Path is selected along the top bar. Also, ensure that the tab Show Elevation Profile is selected. Your length of measurement can also be changed here, in order to fit the necessary units of the question.

7 EXAMPLES Now that we have set up Google Earth Pro, properly, and have learned how to navigate the main window, let s try a couple of example problems so that we know what to expect. Ex 1) We want to know the slope of a section of road in Mankato, MN, from the corner of N 5th Street and E Main Street [ , ] to the corner of Hinckley Street and E Main Street [ , ]. First off, we will create a placemark at each of those latitude and longitude coordinates. Next, we will want to create a line with which to measure elevation and distance on the map. Select the Ruler tool, make sure that you are under the Path tab, and make sure that Show Elevation Profile is selected. We also want to make sure we are measuring as close as possible to our placemarks. To do this, we must place our points as close as possible to the tip of the pin on the Placemark symbol. You may have to zoom in very close to accurately place this point. Use the ARROW KEYS to navigate to your next point. If you attempt to click and drag you will end up placing a ton of unwanted, inaccurate points. Finally, MAKE SURE YOU CLICK SAVE. This will save your path under Places. Your line will look like the image to the right. I have changed my line color to RED to make it stand out better, but that is not necessary.

8 Next we would like to calculate the slope. If you did everything correctly, your window should resemble the image below. The elevation profile should have been opened up and will appear underneath the satellite imagery. If you did not have Show Elevation Profile selected, you will need to open it up. In this case, look for your line under Places. Right click on it and select Show Elevation Profile. Your screen should then match the image above.

9 To determine slope, move your cursor all the way to the left side of the elevation profile graph. Record the value that is displayed in feet. In this example, the number is 834 ft. Then, put your cursor to the right side of the elevation profile graph. In this example the number 990 ft. Locate the total distance, found in the top bar of the Elevation Profile window. In this example, the total distance of the line is 1370 ft. This number will automatically display in miles if the distance is great enough, so make sure to pay attention to the units used. From here, we simply calculate the change in elevation divided by the change in distance and multiply the result by 100 to get a percentage of slope of the line: (!!" $%&'() $% *(+" $% )x 100 = % Ex 2) Now, using the same line as you did above, find the slope (%) between ft on the elevation profile. To do this, we will go back to our elevation profile from the last problem.

10 We want the slope between 750 ft of distance on the profile and 1000 ft of distance. To do this, we will place our cursor over 750 ft, click, and drag all the way to 1000 ft (In this case, the Elevation Profile Window in Google Earth did not seem to like the number 1000, and would not let me land directly on it) For our purposes, the 999 ft value will act as 1000 ft. Just as before, we will simply calculate the change in elevation divided by the change in distance and multiply the result by 100 to get a percentage of slope of the line: (!6! $%&!7' $% 78" $% )x 100 = %