Where to find more Coordinate Systems for Download?

[AlexanderBrodylo]

Essentially, I am lacking a number of coordinate systems necessary for multiple data sets that I am working with. I was wondering if there might be any library or archive online through which you can download more projections and coordinate systems?

I couldn't find any with Esri.

I have Arcmap 2.10.2.2 (something like that).coordinate systems data‌

Any help or suggestions are appreciated!

projections‌projections and transformations‌

spatial

coordinate-system‌

datums‌

[DanPatterson_Retired]

short of modifying what esri supports maybe you could provide a list of a few in  case they have an alternate name..

MKennedy-esristaff‌ ... for you

[AbdullahAnter]

Check this site : Spatial Reference List -- Spatial Reference

You can search inside the site and download .prj file .

[AlexanderBrodylo]

Hmm, will try this later after work.

[MelitaKennedy]

If you have EPSG well-known IDs for the coordinate systems--like 4326 = WGS84--you can type them into the search box. 

If you have a list, you could post or email me and I can tell if they're available under a different name or in a later release.

mkennedy at esri dot com

[VinceAngelo]

There are an infinite number of coordinate systems that could be added, but only in the context of a finite number of known projections. Only Esri can add to the projection list (at least, if you wanted to deproject from it or project to it), but you could create a new CS string based on a known projection with alternate distance units or a custom prime meridian.

Each new release of ArcGIS has a Projection Engine update, so the easiest way to increase the probability of your coordsys being supported is to make sure you're using a recent build of ArcGIS

- V