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Projection Transform in Layer/*.lyr file in MXD

Question asked by jwfox1 on Jul 15, 2016
Latest reply on Jul 16, 2016 by jayanta.poddar

I have a GIS Information Architecture question that has a few of us runing in circles in our shop of late.



How does one apply a projection transformation within an MXD? I have data from an SDE database in NAD83 but need

it transformed into WGS84 Web Mercator in the MXD so it can be published as Web Mercator to web services to

avoid the "projection o n the fly" performance penalty when said web services are consumed over the internet. I

have been approached with maintaining redundant copies of the data in SDE, in each projection synched with database

triggers but my team feels that this is an inefficient solution that may be quite brittle.



The examples I have found apply the transformation in a layer in an MXD but have found no layer "XY Coordinates" layer

projection property to apply the tranformation on. Only source which will transform the base SDE data, which is not what we want to do!


Our data is edited in NAD83 via Desktop but needs to be consumed over the web in Web Mercator (ideally in an

efficient manner) 



If I save off the layer into a .lry file, there is a projection transformation function but again it will override the source

data and not transform it in the layer only. Would this transformation be better done at the publish web service level? I

see lots of discussion on web service caching but not on these types of transformation doing in the web service itself

(Hopefully I am missing something here?) 



I am sure this has been resolved elsewhere in large GIS shops, any thoughts?