Creating a Referential

You can create referentials to describe geographic areas. Once a referential has been created, you can then import or add new datasources to it.

Before you begin:
  • You must not create a referential each time you create datasets but select an already existing referential instead, whenever appropriate. Keep in mind that you cannot mix data from different referentials in the same experience, even though these referentials have the same projection and bounding box. However, this does not apply to datasets in preview (datasources) which are compatible with all referentials.
  • Referentials can be neither deleted, nor modified.
See Also
About Datasets
  1. From the Referential section of the action bar, click Create City Referential .
  2. Define the following parameters:
    OptionDescription
    City Referential Name Name of the city referential.
    Coordinate Reference System (EPSG code) Projection in a coordinate referential system (CRS) (for instance, EPSG 3414).

    You can either directly enter the identifying code, that is EPSG:xxxxx (xxxx corresponding to a 3- to 6-digit code identifying the projection) in the box, or select a predefined CRS from the list.

    If you do not know the CRS code to be used, search for it in the EPSG registry. To do so, access the online EPSG Geodetic Parameter Dataset registry at the following address: http://www.epsg-registry.org/.

    Note: No other WKT projection is supported.
    Square bounds
    • x min and y min: coordinate of the left lower corner in the given projection (for instance, "34308.159446, 30267.235304").
    • x max and y max: coordinate of the right upper corner in the given projection (for instance, "49915.040981, 20951.97629").

    xmin is the left side of the bounding box, xmax is the right side.

    Important: You must imperatively define a zone with all four sides equal, that is (xmax-xmin)=(ymax-ymin)).
    If no error is detected, the new referential is created and the server sends the url of the newly created referential, captured by the UI.



    Important:
    • The referential is always oriented with the Y axis downwards.
    • The referential can be seen by all users of the service on the same platform.
    • For each created referential, the data server keeps the data associated to the referential in its own database. This means that you cannot search for a referential using the Search box.