Zoom in Further in Portal

[ShannonGrumbly2]

Hello! We currently are using basemaps provided by an external source. We contribute money to have the high resolution imagery that this organization then hosts for us, as well as for other organizations. Unfortunately the settings on the tile service only allow for zooming at the 1:141. As a gas utility, we often have dense areas of assets and must be able to zoom in much further to see all detail (e.g. at a regulator station). Giving every end user a license for Pro is not an option, so all of their data exploration must occur in the web map in Portal (10.7.1).

I looked into creating my own tile service and placing it below the imagery. My hope was that the web map would allow the end user to continue zooming in past the 1:141 scale, utilizing this newly created tile service that contains just a curblines feature class and no zoom restrictions. I am having trouble making the map recognize the zoom levels on the new tile service, as it does not let you zoom in past the 1:141 scale at all.

Has anyone ever tried this before (setting 2 tile services to act as the basemap) with success? Perhaps I am approaching this wrong.

Thank you!

[SamLibby]

I am not sure if there is some kind of artificial floor where you cannot zoom in farther, but as I understand it...:

The scale levels of the map viewer are defined by the tile levels of the basemap layer (or should be). So I think you're on the right track with your approach, but maybe mixing the layers into the basemap made it take the smallest scale as the floor. 

I'd suggest starting a new web map, adding your own tile service as the only basemap layer, and then seeing what happens at that point with the zooms. If the imagery layer is a compatible spatial reference, it should be able to be overlaid on top of that basemap as a normal layer, not as a "second basemap layer".

[ShannonGrumbly2]

Thank you @SamLibby !

I am still working through publishing my own tile service with these zoom levels. Of course it comes at a huge storage cost! Seeing what my options are for hosting...

As for the imagery as a regular layer, this is problematic in that the end user can no longer use the basemap gallery widget to select a different year of imagery. I suppose I could make all of the basemaps as "layers" in the layer list, but there is about 25 so it is not ideal. I wonder if there would be performance issues as well, even though they would be turned off. Just a thought.