Geocoding is the technical term that describes the process of converting an address or a description of a location into GPS coordinates or a map. When you only need to convert a handful or location data, the process is pretty straightforward even when you do it manually. But when your data is in the hundreds or thousands, manual geocoding becomes more tricky, burdensome, and prone to errors.
The accuracy of your data determines its integrity, and this is where ShowMyMap comes in.
ShowMyMaps smart tools make the process of accurately geocoding multiple addresses easy. ShowMyMap makes use of Google Map’s geocoding API to generate high-quality data – which is a much sought-after online commodity these days.
ShowMyMap makes generating custom, interactive maps as easy as just making a few clicks! You’ll use your own location data or any open data you can find online to create a map that will suit your needs. Any map you create using ShowMyMap can be shared privately or publicly; you can even embed it on your website!
Geocoding 101
There are different ways that you can map addresses and convert them into GPS coordinates. The various types of geocoding methods also have varying degrees of accuracy, so choosing the right one to meet your map’s intended purpose is important. Here are the two most commonly used geocoding methods.
Interpolation Geocoding
This involves the mathematical interpolation of locations to get their approximate positions. For example, let’s convert 160 Main Street into geographic coordinates using interpolation geocoding.
First, the geocoder will narrow down the area by matching the street name – 160 Main Street – and the direction/orientation and street type against a block range using a street centerline database. The city name or postal code will be used to differentiate this particular Main Street from other Main Streets.
Once the correct street has been identified, the geocoder will further narrow down the area to the closest block on Main Street that covers the given street number – in this case, the block that contains numbers 100-200.
The actual interpolation comes next. This involves an approximation of 160 Main Street as a little more than the block’s halfway point, after 150.
Interpolation has several stages, each of which involves narrowing degrees of approximation based on a combination of logic and database referencing. This is why interpolation geocoding is the most prone to errors and the least accurate method.
Parcel Geocoding
Parcel geocoding makes use of centroids or property boundaries assigned to specific addresses. The geocoder attempts to find the closest match to the address searched for – 160 Main Street – against an already identified parcel address.
Parcel geocoding is more accurate than linear interpolation because it uses stricter matching criteria. Whereas interpolation only narrows down the area to the closest possible vicinity using nearby points and does not pinpoint the exact location, parcel geocoding actually locates the exact property in question using known boundaries so that accurate coordinates can be assigned to it.
To search for 160 Main Street, the geocoder will look up the specific address in the parcel database. Differentiating this particular Main Street from other Main Streets will involve parcel-level data, instead of block-level data – which effectively narrows down the search field to a smaller and more accurate geographic area.
Geocoding Using ShowMyMap
ShowMyMap utilizes geocoding data made available by Google Maps which, in turn, employs the parcel geocoding method for their geocoding API. This is how we ensure accurate results. We also use DivShare to make the conversion of your location data convenient and efficient.