Hi there,
my map (ArcGIS desktop 10.5) has been assigned a local coordinate system (GCS_CH1903+). I add a WMS layer from a server which provides the data in the aforementioned local coordinate system but ArcMap does not recognize it. A dialog pops up with a warning telling me that the transformation from WGS_1984 is required.
Why is that? Why doesnt recognize ArcMap that the data is available in a local coordinate system and therefore no transformation is required?
Many thanks, Rob
I think the WMS layer is not in a local CS. WMS Servers support only a limited number of coordinate systems.
Please check this Setting the coordinate system of a WMS service—Help | ArcGIS Desktop
If the data frame is in a coordinate system that is not supported by the WMS server, ArcMap gets an image from the server in a supported coordinate system—in most cases, this will be in GCS 1984—and projects this image internally so it will display in your map.
Hi,
my data frame and the wms layer have the same coordinate system:
data frame -> coordinate system:
CH1903+_LV95
WKID: Authority: 2056 (EPSG)
WMS - Layer properties > Source > Data Source
Supported Coordinate Systems:
EPSG:2056 - CH1903+_LV95
EPSG:21781 - CH1903_LV03
EPSG:4326 - GCS_WGS_1984
.....
All values above copied and pasted from ArcMap.
But when I add the WMS layer to the data frame I get a warning: "WMS datasource uses different coordinate system than data frame." - I dont want to transfrom from WGS84 to CH1903+_LV95 as the data is already provided in CH1903+_LV95
Rob