First things first, we need data to work with. Before we can start fiddling around with ArcGIS Online and web maps, we need to ensure that our data can be visualized on a map in the first place. Of course, the best candidates for geographic visualization are datasets that include location data (latitude/longitude, geographic coordinates, addresses, etc.), but in reality, most projects don’t record this information. In order to provide an example of how a dataset that doesn’t include location information can still be mapped, we’re going to work with this sample dataset that I downloaded from FigShare. It contains 1,000 rows of IP addresses, names, and emails. If you already have a dataset that contains location information, you can skip this section and go straight to “The Web Map.”
In order to turn this data into something that’s mappable, we need to read the IP addresses and output their corresponding location information. IP addresses only provide basic city-level information, but that’s not a concern for the sample map that we’ll be creating here. There are loads of free online tools that interpret latitude/longitude data from a list of IP addresses, so you can use any tool that you like – I’m using one called Bulk IP Location Lookup because it allows me to run 500 lines at a time, and I like the descriptiveness of the information it returns. I only converted 600 of the IP addresses in my dataset because the tool is pretty sluggish, and then I used the “Export to CSV” function to create a new spreadsheet. If you’re performing this exercise along with me, you’ll notice that the exported spreadsheet is missing quite a bit of information. I’m assuming that these are either fake IP addresses from our sample dataset, or the bulk lookup tool isn’t working 100% properly. Either way, we now have more than enough data to play around with in a web map.
The Web Map
Now that our data contains location information, we’re ready to import it into a web map. In order to do this, we first need to create a free ArcGIS Online account. After you’ve done that, log in and head over to your “Content” page and click “Create → Map” to build a blank web map. You are now brought to the Map Viewer, which is where you’ll be doing most of your work. The Map Viewer is a deceptively powerful tool that lets you perform many of the common functions that you would perform on ArcGIS for Desktop. Despite its name, the Map Viewer does much more than let you view maps.
Let’s begin by importing our CSV into the Web Map: select “Add → Add Layer From File.” The pop-up lets you know that you can upload Shapefile, CSV, TXT, or GPX files, and includes some useful information about each format. Note the 1,000 item limit on CSV and TXT files – if you’re trying to upload research data that contains more than 1,000 items, you’ll want to create a Tile Layer instead. After you’ve located your CSV file, click “Import Layer” and you should see the map populate. If you get a “Warning: This file contains invalid characters…” pop-up, that’s due to the missing rows in our sample dataset – these rows are automatically excluded. Now is a good time to note that your location data can come in a variety of formats, not just latitude and longitude data. For a full list of supported formats, read Esri’s help article on CSV, TXT, and GPX files. If you have a spreadsheet that contains any of the location information formats listed in that article, you can place your data on a map!
That’s it for part one! In part two we’re going to visualize our data in a few different ways and export our map for presentation.