The Meta-Geocoding module from Spatialytics ETL is a tool used to geocode data by using existing external geocoding engines (via exposed Web Services / APIs). It can use many geocoding engines - Open source or not, free or not - that are known on the market. Among these engines are:
The engines listed above allow the Meta-Geocoding module to offer geocoding and reverse geocoding capabilities. Geocoding is the action of attributing geographical coordinates (longitude/latitude) to an address. Reverse geocoding is the opposite.
The Meta-Geocoding module takes in input text data that can be transformed using Spatialytics ETL steps and gives as output a point type geometry. Accordingly, reverse geocoding takes points as input and gives addresses as output.
Here are the installation instructions for the Meta Geocoding Module:
Then launch Spatialytics ETL and the Meta-Geocoding module will appear under the name Geocoding Module in the Transform section. You can then use it as any other Spatialytics ETL step.
The use of the Meta-Geocoding module is the same as any other step. Follow these instructions to configure it.
Section A: Geocoding Name and Type
Step Name: This is where the step name is typed
Geocoding Type : This is where the user can choose between geocoding or reverse geocoding.
Section B: Service Configuration
Geocoding Service : The user can choose the geocoding engine here. It can be Google, Yahoo, OpenAddress, etc..
Service URL: Used to type in the URL of the geocoding engine. For most of the engines except Semantic Media Wiki, the user does not have to specify the URL as it is automaticaly entered.
Filter by: Allows the geocoding filtering by administrative regions, airport, country, intersection, municipality, etc. Unfortunately, this function is not supported by all engine.
Provide API key : Use this button to type in the API key of the choosen engine. This key is necessary to use the geocoding services of the engine.
Section C : Autres options
Get first match row only: If this box is not checked, all the results of the geocoding of a specific address are sent back. If it is checked, only the first result is sent back.
Field to geocode: Specifies the column to be used for geocoding or reverse geocoding. For a geocoding operation, the column must have an alphanumeric type. For a reverse geocoding operation, the column must have a geometry type.
Result field name : Specifies the column where the result of the geocoding will be stored.
Add full address from engine: When this box is checked, the Meta Geocoding module returns the full address that the engine used for geocoding. This allows the user to update his database with this address. Note that this option is not available for a reverse geocoding operation.
Full address field name : When the Add full address from engine box is checked, this field specifies the field name of the full address returned from the engine.
See the following transformation:
The Meta-Geocoding module receives data from a file.
Step 1: Configure the Meta Geocoding module
In the figure above, we can find the following configuration:
Step 2: Preview the result
For the Google geocoding engine, please refer to their geocoding API documentation at https://developers.google.com/maps/documentation/geocoding/#Results.
For the Yahoo! geocoding engine, please refer to their geocoding API documentation at http://developer.yahoo.com/boss/geo/docs/supported_responses.html#address-quality.