Different Spatial References in Basemaps - ArcGIS Viewer for Flex

[GregSnelling]

I noticed when adding the ESRI World Imagery Service to ArcGIS Desktop, the transformation is applied automatically match my data-frame's coordinate system.  Is there a way to do this in the Flex Viewer?  The reason is because I have a custom basemap I'd like to use with a different spatial reference than the ESRI World Imagery.  Rather than transforming my custom basemap, I'd like to transform the ESRI World Imagery basemap.

[RobertScheitlin__GISP · Accepted solution]

Greg,

  ArcMap is designed to be able to handle on the fly reprojections with great speed. This something that you really can not do anymore in ArcGIS server unless you want to loose the speed if the cached map service and switch your World Imagery to dynamic. I personally have a replicated geodatabase of all my data in web Mercator and have this automated to reconcile the replica every night to get the latest updates. That way I can use ESRI base maps and just add my web Mercator data to it.

[GregSnelling]

Thanks Robert.  That's good advice.  I believe it's definitely worth it to be able to use the free ESRI basemaps.

[RobertScheitlin__GISP]

Let me know if you need me to dig up the white papers on how to do this.

[GregSnelling]

I used "batch project" geoprocessor to create an identical file geodatabase web mercator coordinate systems.  I then republished the map service. 

I've created a test flex app and added my new web Mercator tiled service and the ESRI World Imagery basemap.  For some reason they are still not displaying together.  When I add my own basemap at the top of the basemap layers, the viewer will open and display fine; but when I choose the ESRI basemap, I get white space.  If I then change the ESRI basemap to display first in the layer TOC, then the ESRI basemap displays fine, but when I choose own basemap, I get the white space.  I checked the spatial references for both of these tiled services and they are both web-Mercator (Spatial Reference: 102645  (2229).   Any ideas?

[RobertScheitlin__GISP]

Greg,

   Is your basemap cached at the same scales as esri's? Also the wkid for WebMercator is 102100 or 3857, 2229 is NAD_1983_StatePlane_California_V_FIPS_0405_Feet. Are you sure you reprojected your data?

Check out this KB with is the process I use: 34129 - Create a replica where the child replica data is in a different coordinate system than the p...

[GregSnelling]

Oops.  You're right.  For some reason the service didn't publish as Web Mercator.  I had reset the data sources in my .mxd to the geodatabase replica, but they maintained the definitions in the layer properties for some reason.  So I've started with a fresh .mxd and re-added my web Mercator layer, saved and published.  Now the map service looks correct, showing Spatial Reference: 102100  (3857).

I guess I should know by now that 2229 is my local coordinate system, my bad.

Thanks so much for your help Robert.