Uploading raster: GCS_WGS_1984 vs WGS_1984_Web_Mercator_Auxiliary_Sphere

[JonasArdö]

Trying to upload a File Gedatabase Raster Dataset to ARCGIS online but when I try to add it to my WEBMAP (containing "world tansportation" and "imagery with labels") I get an error message:

The layer, NPP_TEST, can not be added to the map because its coordinate system or tiling scheme can't be adjusted to align properly with the basemap" even if the georeferemceing is identical in meta data.

Is data in GCS_WGS_1984 (degrees) recalculated to WGS_1984_Web_Mercator_Auxiliary_Sphere ?

What is the simplest way to upload raster in  GCS_WGS_1984 to a WEBMAP using a tiling scheme in WGS_1984_Web_Mercator_Auxiliary_Sphere?

[AnthonyGiles]

As far as I am aware cached datasets will not be re-projected on the fly this will only occur for a dynamic service. You could try setting your base map in the map viewer to a WGS84 service:

ESRI_Imagery_World_2D (MapServer)

otherwise I think you need to reproject your raster dataset.

Regards

Anthony