We source location information from our global data suppliers, including Ordnance Survey UK and TomTom and combine this information with our address data to provide location and associated accuracy for every address we capture.
A sample result is shown below:
"location": {"latitude": 40.863013,"longitude": -73.922423,"crs": "EPSG:4326","accuracy": "BUILDING"}
The CRS is the Coordinate Reference System. Our location object always returns a latitude, longitude coordinate, in this case 4328 is the code for latitude, longitude in WGS84 which is the standard used globally by sat-navs, Google Maps etc. In Europe some addresses may be returned in 4258, which is the European standard. Differences between 4258 and 4328 are so small that they can be safely ignored.
The accuracy parameter indicates the accuracy of the returned coordinate, with the majority of our location information available at BUILDING (rooftop) level. Where rooftop accuracy isn't available for an address we return a coordinate with less accuracy as per the table below.
| ACCURACY | DESCRIPTION |
|---|---|
| BUILDING | Rooftop accuracy |
| STREET | If we don't yet have a building coordinate for an address, but we do have coordinates for other addresses on that street, then we assign the address a street level accurate location. |
| POSTCODE | We have building level coordinates for the vast majority of addresses in UK and Netherlands, however some newer addresses may be missing a building level coordinate. As UK and Netherlands postcodes are small enough to provide accurate location information, we return the coordinates of the centroid of the postcode. |
| LOW | For bigger postcodes (e.g. Zip codes), City level accuracy, etc. we return an accuracy of LOW. |
For some countries we provide coordinate information in their local map projection, e.g. gb_location will return Easting, Northing in UK National Grid.
