Dear All,
I really surprised by the extra steps need to take to change the coordinate system of ArcGIS Online Map. I can set my coordinate systems correctly on ArcGIS Pro, and publish a map to ArcGIS Online. However, it won't use the exact same coordinate systems that I set up on ArcGIS Pro. Isn't that interested?
Then, I started searching how to use my own UTM coordinate system instead of using LL84/Pseudo Mercator. I found this helpful YouTube video published by Esri Canada.
(3) How to Change the Projection in ArcGIS Online - YouTube
When I first saw this video, I don't know if I should be happy or be sad.
I have been using Open Source web GIS solution called MapGuide for years, and even the coordinate systems of the Open Source web map can be configured to different one anytime. It will also convert all the vector (not raster) data to the target coordinate systems on the fly.
I can use basemap with my specified UTM coordinate systems without any issues using ArcGIS Pro, and I believe ESRI can achieve the same functionality on ArcGIS Online web map as well. Please allow the end user to change the map coordinate systems anytime. It will make ArcGIS Online/Portal even greater!
Cordially,
Reno