What is Geocoding?

Geocoding Basics

The boring answer is that geocoding converts information about a location to specific positions on a map. A simple example would be latitude and longitude converted to a street address.

Sure, it’s boring but ask yourself if you’d rather drive to 37.3387° N, 121.8853° W, or 1121 North Market Street?

The output of this geoprocessing might be a spreadsheet that can be fed into various software applications, which then transform the data into a format usable by applications. You will often see this data displayed on a map as points or some other symbol, such as a burger for restaurants.

Though they appear simple, those points or symbols might contain a wealth of information categorized by different attributes and data types.

The data could be comprised of anything but most commonly includes names, mailing addresses, phone numbers, elevation, etc.

If you pay attention, you’ll notice that this information is utilized everywhere. It could be an app developed for theme parks to guide you to attractions and display ride times, walking tours of historic places with links to audio content, or simply searching for the nearest restaurant on google maps.

The next time you’re looking for the closest burger place on your phone, you can thank geocoded data for providing the location of that tasty meal.

Geocoding Data Issues

Who doesn’t enjoy waiting hours for data processing to finish only to receive some obscure error code at the end? While the error codes and debug programs have certainly improved over the years, this can still be an arduous task.

The best advice is to start with the basic stuff before moving on to more complex solutions.

  • One of the most common problems you might encounter when using geocoded data is when you find two addresses on one property. There are a variety of ways that you can fix this problem, but you should always start by examining the source or reference data that you used for address matching.
  • If you utilized a geocode service, reach out to their support team for assistance with validating the address dataset before you do anything else. You don’t want to waste time fixing a problem that isn’t yours.
  • If you can’t spot any obvious issues with your dataset, such as pointing at the wrong attribute instead of the address field, then the next step should be to validate it through another source.
  • The easiest validation method would be using an application such as google maps to compare the geocoded address vs street address displayed. By examining the properties nearby, it should be obvious which of the duplicate addresses is correct.
  • Another option you could try is looking for the assessor’s parcel number or APN from the local county or city. These excellent sources will likely have the most up-to-date address data and are generally available in a downloadable format.

Occasionally, this data is free but be prepared to pay a fee most of the time, especially if you request a large amount of data. Many city and county GIS departments are understaffed and probably underfunded.

Some agencies might not have any GIS data at all, with paper records being their only source of property information.

If you are lucky, they will send you scans of these documents. If that is not the case, then you might want to familiarize yourself with some ancient technology called microfiche. All you can do at that point is pray they were organized and well maintained. Be sure to set aside plenty of time to comb through them all!