Adding point data. Account not required

Transcription

1 Adding point data Find patterns in mountains of data You begin to get a strong sense of what maps can do from this lesson. The image shows a total of 58,000 airline routes on one map. The Web Mercator projection transforms the straight flight paths into curves. You are going to use this map to solve a spatial problem while also learning how GIS software deals with point data. Locational information contained in point data adds the spatial component that the map needs to locate the information. Point data can get its locational information from latitude and longitude or from a street address. Account not required Build skills in these areas Opening and modifying an existing online map Filtering Adding x,y data Geocoding data Creating bookmarks What you need Account not required Estimated time: 30 minutes 1 hour 1

2 Scenario The International Federation of Air Traffic Controllers Associations (IFATCA) wants to investigate flights going in and out of three of the busiest places in the world: London, New York, and Atlanta. The federation wants a visual representation of the flight routes to each of the airports within the three cities. Confrim that you want to search in ArcGIS Online. Open the map, add and filter data 1. Click Airflow Pro. 2. In the upper right corner, click Modify Map. 3. In the top menu, under Details, click Content. You should see two layers in the Content pane: World Dark Gray Base and flight routes. 6. Add World Cities by esri by clicking Click back arrow by ArcGIS Online. You have been asked to map three individual cities that have the largest air traffic: London, New York, and Atlanta. You need to add a layer to obtain that information. 4. Click Add on the Top menu and choose Search for layers. 5. The search pane opens. In the search box, type World Cities owner:esri. In: ArcGIS Online. As you zoom out, both layers disappear. This is because a visibility range has been set. Visibility range is used with multiscale maps and allows you to view geographic data across a range of scales or zoom layers. The next two steps set the visibility range to be at all scales. 8. Click the three dots More Options and select Visibility Range. 2

3 9. Change the slider to go from World to Building. (You can specifically set the scale to be 1:18,000,000 or you can move the right to buildings and leave the left on world.) You now want to narrow down the cities to London, New York, and Atlanta. You do this by applying a filter, which presents a focused view of the feature layer World Cities. 10. Point to World Cities and click Filter. 11. Create your definition expression. Be sure to select Any. CITY_NAME is London. (Type London.) Be sure to click Unique. + Add another expression. CITY_NAME is New York. (Type New York.) + Add another expression. CITY_NAME is Atlanta. (Type Atlanta.) Click Apply Filter. At the top of the Filter Menu be sure you change the setting to match any of the following expressions. Locate and map airports Now that the three cities are isolated, it is time to locate and map the individual airports. To add the location of the individual airports, you will deal with two types of point data. Type 1: Add the first set of airports to the City of London by using latitude and longitude (x,y) data. Type 2: Add the second two cities (New York and Atlanta) with address information. Add this feature data from a delimited text file (.txt) or a comma-separated values text file (.csv) that includes the locational information (latitude and longitude or address) along with any other attributes. What follows is an example 3

4 of a delimited text file for the London airports with latitude and longitude data. Notice how the headers are separated by commas with no spaces. That is why it is called a comma delimited text file. The name of the airport is the only attribute attached to the locational information. Notice also that the latitude and longitude are in decimal degrees. These must be exact and on one line and with no spaces. Long,lat,name , ,Heathrow , ,Gatwick , ,Luton , ,Stansted , ,Southend Copy the text above exactly as shown into a 1. simple text application. Notepad is a great application to use for this. Be sure to copy the top line: long,lat,name. It must look exactly like the text above. 2. Save the file on your computer and name it airports_x_y. 3. Drag the airport_x_y file to your map. Change symbology 1. The airports are displayed by Types (Unique symbols) with the attribute as the name. Click OPTIONS. 2. Click the color ramp to activate the change symbol menu. 3. Move the Symbol Size to 15 and choose a shape. 4. Click OK. Click OK again. 5. Click Done. Geocode Add the second two cities (New York and Atlanta) with address information. Geocoding is the proper term for converting an address to an x,y coordinate. By default, ArcGIS Online uses the World Geocoding Esri service. This is the power of GIS. You have taken a table of data and mapped it. If you click on any of the points, you can see the locational information as well as the name of the airport. At the top of the next page is what you need for a comma-delimited text file for New York and Atlanta. 4

5 4. Name the bookmark London. Name,address,city,zipcode Laguardia,LaGuardia Rd,Flushing,NewYork,11371 John F Kennedy Int'l Airport,678 S,Jamaica,New York,11430 Hartsfield-Jackson,6000 N. Terminal Pkwy,Atlanta,GA, Type the above lines exactly as shown into a simple text application (like Notepad). 2. Save the file on your computer and name it airports_addresses. 3. Drag the airport_addresses file to your map and ADD Layer. 4. Match the symbology of the UK airports as set previously. Create bookmarks To get quickly from airport to airport on your map, as the map author, you need to create bookmarks. Bookmarks are based on the current location and scale of the map. When others click a bookmark, the map zooms to that location. 1. Zoom to the location and scale that you want to look at for London and its airports. You might want to change the basemap. 2. On the top of the site, click Bookmarks. 3. Click Add Bookmark. 5. Click the X in the upper right corner to close the bookmark. 6. Zoom to New York and create a bookmark. Name the bookmark New York. 7. Zoom to Atlanta and create a bookmark. Name the bookmark Atlanta. By completing this map, you have given the IFATCA a visual representation of the flight routes to London, New York, and Atlanta. To do that, you used the following GIS skills: Searching for ArcGIS Online layers Filtering layers Mapping table data with an x,y coordinate Mapping table with an address Creating bookmarks 5