aerials and streets don't line up

[ErikBlake]

I am trying to publish my own basemap service. I set my data frame to web mercator have my streets layers in web mercator and changed our aerials projection to web mercator in ArcCatalog by: Right clicking on aerial then in properties changed from ohio state plane north to web mercator.

added all layers to my ArcMap 10.3.1 and they don't line up with each other, Do I need to reproject the aerials a different way?

[DanPatterson_Retired]

if the files had a defined coordinate system in the first place, you shouldn't have to redefine anything in the first place?

If the offset is big, then the file or files have been defined wrong.  Either redefine them back or give them a correct definition in the first place.  You can Project them to a common projection, but you shouldn't need to... just ensure they are defined correctly

[NeilAyres · Accepted solution]

You do not "change projection" of a dataset by just resetting the properties of the dataset.

So change it back. To permanently change the dataset coord sys, you have to re-project to another coord sys.

But as Dan said, when publishing a service, its just the data frame coord sys properties that need to be set to Web Mercator, all the rest will be re-projected on-the-fly.

[ErikBlake]

Very good Neil. Thanks for the clarification. I was always under the impression that datasets, layers, and data frame had to be web mercator. Not just the data frame. I appreciate you expounding on this matter.