GeoIQ Geocoder

GeoIQ built the geocoder powering GeoCommons and GeoIQ appliances in order to provide users with an easy way to georeference their data from spreadsheets. The Geocoder works in the United States to the street level using the US Census road data and internationally to the city level using the Geonames gazetteer.

The GeoIQ Geocoder is open-source and available from our repository at http://github.com/geocommons/geocoder.

What is Geocoding?

Geocoding is the process of finding geographic coordinates from other geographic data, such as street addresses or ZIP codes.
The built in geocoder within GeoCommons makes it simple to retrieve longitude and latitude coordinates from your locations based CSV files. The geocoding process has been fully integrated into the upload process, and will retrieve coordinates based upon the location based values found in your CSV file.

Required Geographic Data for GeoCoding

There are many types of geographic data out there but the GeoCommons GeoCoder will only accept certain types of geographic data for GeoCoding purposes. By having these data types in your CSV, the GeoCoder will be able to take your uploaded data and assign latitude and longitude coordinates to the data for mapping purposes. Below are the accepted data types that will work in the GeoCoder.

What can the GeoCoder not GeoCode?

If your CSV does not have one of the above combinations you will receive an error during the upload process into Finder! Below are some unaccepted combinations that will cause an error:

Be sure your street addresses do not contain PO Box numbers. The GeoCoder is not able to GeoCode such locations and will give latitude and longitude coordinate results based on the postal code/ZIP code given in the CSV.

Preparing your CSV for GeoCoding: Single Field and Separated Fields

So how do you make a CSV with geographic data ready for GeoCoding? These tips can help you learn the correct methods when preparing a CSV for GeoCoding.

When formatting your CSV for upload, you can either breakdown your file into basic fields or you can place them together in a single field. Below is an example of a CSV that has been broken down into parts:

Please note that each row of your spreadsheet will represent one point location to the geocoder and eventually any maps created from your data.

As you can see above the address/city/state/country/ZIP code fields are separated into different columns. When the GeoCoder receives this file it will take the separated fields, recognize their geographic types, combine them appropriately, and then GeoCode for latitude and longitude results.

Your geographic data can also be combined into a single field. See the example below:

When combining the data into one address form, there are a few things to keep in mind to allow for the best possible GeoCoded results.
  1. Use commas to separate the different geographic fields
  2. Keep the fields consistent
    • Use same separators (commas) in all attribute entries
    • Use same geographic types in all attribute entries

By following these formatting guidelines, you will be able to successfully GeoCode your data in the GeoCommons GeoCoder.

Saving my Excel Spreadsheet as a CSV

Once you have properly formatted your spreadsheet you will want to save it as a CSV file. This can be done following these steps in Microsoft Excel:
  1. Select the Save As option from the Excel options dropdown.
  2. Choose the location you wish to save your file to.
  3. Title your dataset in the File Name: field.
  4. Select the Save as type: CSV (Comma Delimited) option from the drop down menu.
  5. Finally click the Save button.

Please note that when saving a CSV file multiple sheets cannot be saved. After clicking the save button you will be prompted with this information. Please make sure that you do not have any important data on any sheets other than the one you wish to save.

Uploading your CSV and GeoCoding

Now that you have your file saved as a CSV, you can upload and GeoCode it in GeoCommons. Starting on the GeoCommons Homepage, follow the instructions for Uploading Files from your Computer

After Adding you file, you will be taken to your Pending Layers where you will click Next Step to start the GeoCoding process.

Formatting Your Data During the GeoCoding Process

The first step in the GeoCoding process is to choose to GeoCode based on an Address or Place Name.

From there you will guided through a step by step process where either GeoCommons will easily recognize your address in which case you can choose to Continue or you can direct the GeoCoder as to what data should be used in the GeoCoding process by chooseing select different columns.

Later in the process you will have the opportunity to edit any data that was not GeoCoded properly.

If you choose to select your own columns for GeoCoding, you have the opportunity to format each data column in order to specify which type of address data you have.

For each column you can specify the type of data by choosing from format options in Addresses, Geographic and Standard. Your data will be classified by default but you can change it if a different class is more appropriate.

Address Attributes

The Address option should be used on all of your data that should be used to GeoCode. By selecting any of these options, you tell the geocoder to include this information in the geocoding process.

Geographic Attributes

The geographic attributes can be used if you already have geographic information in your dataset such as latitude and longitude.

Standard attributes

Please use the standard options for all of your non geographic data. Your standard options are as follows:

Review your data

As mentioned above, once your file has been GeoCoded, you will have the opportunity to review the results and edit the data of any features that were not correctly GeoCoded.

Identifying GeoCoder Errors

GeoCoding large CSV files may be challenging for the GeoCommons Geocoder. Our GeoCoder has a limit of 5,000 rows.

The GeoCoder is able to report to you the number of attribute records that were GeoCoded and those that were not. Your overall match and unmatched totals will be recorded at the top of the page.

After identifying the mistakes, you can double click on the cell with the error and correct it. Click Update for each cell. When you have made all of you corrections you can click Save & Resubmit. The GeoCoder will go back and resubmit the corrections and hopefully correctly GeoCode those features.

If you have received errors or a large number of you entries have not been GeoCoded, we strongly recommend looking back over your CSV that you have uploaded. Check to make sure that the data is formatted cleanly. Also check to see that the data is consistent.

Once your data is correctly GeoCoded, click Continue. Finally, Describe you data providing the appropriate metadata. Make sure you site the GeoIQ GeoCoder as the geocode service used. Save, and now you can map your points. Please see the Describing Your Data portion of this manual for more information regarding this process.