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Define Datum Transformation with ArcGIS Server

Question asked by valraa on Jun 11, 2018
Latest reply on Jun 12, 2018 by MKennedy-esristaff

With the JS API (v. 4.7) I am creating a view which has a spatial reference RDN2008 (EPSG: 6706).

I am using this WMS as basemap, which is in this very coodinate system: https://wms.cartografia.agenziaentrate.gov.it/inspire/wms/ows01.php.

When I import some mapservers in 102100 (or 3857) to use as my operational layers, they are placed in the right location, except a big shift when zooming in details. This is due to the lack of Datum Transformation.

This is one of the mapservers I am using: OT_Demo/ReteAcqua (MapServer).

In ArcMap, I can import both the services (the basemap in 6706 and the mapserver in 102100), have the Data Frame SR set to 6706 and then I can define the transformation "RDN2008_To_ETRS_1989_1 + ETRS_1989_To_WGS_1984". This way, the operational layers match the basemap as I'd like (no shift).

These are basically two consecutive transformations to my understand:

  • RDN2008_To_ETRS_1989_1 with WKID 6710
  • ETRS_1989_To_WGS_1984 with WKID 1149

I found these same two Transformations in the ArcGIS REST API, at this page: Datum transformations—ArcGIS REST API: Services Directory | ArcGIS for Developers.

Is there a way to controlo which (if any) Datum Transformation the REST API is doing?

How can I possibly use one or two consecutive as in my case?

It seems not even ArcGIS Online can handle this correctly (it actually reads the WMS used as basemap in 4258, which is one of the options to get the WMS, and no transformation (I see this from the browser dev tools)).

If that matters, I am using an ArcGIS Server 10.3.1 but I also have access to a 10.6 although I have not tested this there yet.

Thanks in advance for any suggestion.

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