Coordinate System strategies for AGOL

[MattDeFoor]

If we eventually get stuck having to use AGOL/Portal (the web map route) for our WAB sites, are there any major benefits to change from your currently used coordinate system (State Plane GA West for me) to match the ESRI Basemaps?

Flex has never had a problem with the deviation between the Operational Layers and the Basemaps using the REST URLs. But before I go back and re-publish my services to Server, with the additional step of registering the service with AGOL, I'm wondering if I should reproject my services in the WGS 84 Web Mercator and match my scale dependencies to their Layer Levels? Btw, all of my services will be dynamic, no caching.

Anyone have any suggestions on this?

Thanks

[TimWitt2]

Matt,

I think a lot has to do with what you want to do with your application. If it involves a lot of onclick commands or geoprocessing it is a good idea to have everything in your map in the same system. However you are still able to assign spacialReferences to points, polygons and such, if you don;t want to have everything in the same system.

Hope this helps!

Tim

[RobertScheitlin__GISP · Accepted solution]

Matt,

   If you do not reproject your data to web mercator then ArcGIS Server will have to do this each time a map is requested (i.e. each time you pan the map the data will be reprojected on the fly by ArcGIS Server). I would always recommend that you have your GeoDatabase replicated and the replica child will be in WKID 102100 and you just do a nightly geodatabase reconcile with the parent that is still in state plain. This is how I have done it for several years now and it works great. Here is the white paper on creating a child GDB in a different spatial reference. 34129 - Create a replica where the child replica data is in a different coordinate system than the p...

[MattDeFoor]

Thanks Robert. That something I thought about, but I didn't know of an easy way to do it.

I believe this is the method I'll adopt as well.

Thanks again!