Join Jason VanHorn for an in-depth discussion in this video Adding map data to a spatial database, part of Real-World GIS.
One of the easiest ways to collect geospatial data is from the world of online maps. For example, before building a geospatial database, I've interest in locations in London, we could start in Google maps and collect location information and build a table of that information to display in our GIS. Let me show you how to do that. Here is Google classic in the city of London. Whenever I put my cursor on something interesting, such as London Bridge, and a right-click I can choose what's here.
When I choose what's, here notice that we have our latitude and longitude reported in decimal degrees. In this case, Google is using the WGS 1984 ellipsoid. So we can copy this location information into an Excel spreadsheet and begin to build a geospatial dataset. Here in Excel, I'm going to start with the first row and type ID, lat, long and then detail. Here in this example, I'll give my ID a one and corresponding, sequentially up, and then I'll put my latitude and longitude here.
And here I'll put the details related to the feature I'm interested in. We could add in as many columns of detail or attribute information we wanted to. Here I'll adjust Excel to be off to the side as well as my browser for this collection process. Since this is my first feature, I'll make the ID 01. And now, I'll cut and paste the latitude and longitude just as I see it here in Google Maps into my Excel spreadsheet. In this case, I'll expand out my details column and type in the name of the feature.
Now I'll go through and collect a few more features. You can do the same as well. With these four features collected, now let's bring them into ArcGIS. Earlier versions of ArcGIS allow you to bring in an Excel spread sheet, a .xls or .xlsx. However, often when you do this, it's problematic. With the newest version of ArcGIS 10 which is 10.2, Eserie has built a new tool in our toolbox to convert excel spreadsheets to tables.
I'll save my spreadsheet here to the desktop, and then we'll open it up in Arc map and convert it. To find this new tool in ArcGIS 10.2, you can use the Search tool or Navigate In or Toolbox to locate it. Since I don't know exactly where this is at in our Toolbox, I use our favorite feature in ArcGIS, that is the Search tool. I will type in Excel and table. Here we go. I'm interested in the Excel to table conversion tool. Here I will put in the Excel Spreadsheet I just created and put on my desktop.
For this example I'll keep the output table location the same. In this example, I've only created one sheet within my Microsoft Excel document. But if you've created different sheets within a document, you can reference them here. I'll click OK for the conversion. Now let's take a look at that table. Right clicking on the table and choosing to open, we see the results. Notice that our ID, our lat, our long and our detail is preserved. Now let's take this table data and make it x,y data or latitude, longitude data. Under File and Add Data, we can choose to add xy data.
Since ESRI is expecting a long and lat type of column heading, it's already pre-populated for us. In this case, we don't have an elevation-z field. But we do know the coordinate information, in this case we collected this data using Google Maps. And Google Maps uses the WGS84 ellipsoid. So let's go ahead and add that now. Choose Edit, and then we can navigate using geographic coordinate system, world, and WGS1984.
And we can click OK, and now those four locations are added to our map. However, this is just an event. We have to make it permanent by right-clicking, choosing data and exporting that data. We can either export that data as a shape file or a geodatabase. In this case, I'll keep it in my geodatabase as a feature class. And we'll say, Yes to add it to this map. Now I can remove my event. We can visualize the layers. And let's check it by adding a base map to see if it's correct.
Utilizing this methodology, you can quickly create geospatial data from online maps.
- Exploring GIS trends
- Accessing data in proprietary and catalog formats
- Understanding GIS data formats
- Working with scale and graticules in projections
- Collecting geospatial data
- Building a GIS project from scratch
- Mastering GIS job interviews