Reverse Geocoding

Characteristic

Detailed Consideration

Reverse Geocoding with an input coordinate

Reverse Geocoding can be done with the xLocate service endpoint

• searchLocations (Web Service A web service represents a communication technology applied in computer networks. It provides an interface described in a machine-processable format, for example WSDL. API) in combination with the corresponding request type SearchByPositionRequest

which is explained in the Reverse geocoding an input position integration sample.

Search algorithm

The search algorithm is searching for the next address with a certain radius. If no address can be found within this initial radius, the value is automatically increased in order to trigger a new search.
When performing a search, as soon as addresses are found, search is stopped. Then, results are evaluated according to certain criteria in order to decide which are the best. These criteria are:

• If the closest result is an exact address or if there is an exact address approaching the closest result, then the exact address is returned.
• If the closest result is an interpolated address and if there is no exact address close to this one, then the interpolated address is returned.
• If the closest result is a street and if there is no exact or interpolated address close to this one, then the street result is returned.

In the case where no address can be found, even with the maximal search radius (1000 meters) allowed, the next city or postal code center is returned.

Result List

If the request succeeds, the response consists of a list of records, each containing the actual address, its coordinates and the distance in meters from the given input coordinate to the found address.

• The list is omitted if no matching record is found, and the list size is limited to keep the server responsive even with bad input data.
• The records have fields such as the postal code, city or street name, a special type field to indicate the flavor or type of the record and the distance in meters.
• The list is sorted by distance and only records that are in a delta of one meter are kept (the difference between the distance of the first returned record and the distance of the last returned record must be less than or equal to one meter).

Record Fields

Each returned record always have a distance field and can have one or more coordinates and address fields, e.g.:

The availability and content of these fields depend on the record type and the API version used. Please check the API documentation to see which fields are supported in the API version you are using.

Record Types

Record types are returned in the field type.

Common record types are

• locality (e.g. Boston)
• postal code (e.g. 10557 Berlin)
• street section (e.g. Avenue des Champs-Élysées, 75008 Paris)
• address (e.g. 10 Downing St, London SW1A 2AA) .

Good to know

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