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I am using ArcMap 10.3 and I have a data file with xy coordinates (New York City/State) that I'm trying to project properly. Having trouble figuring it out and don't have a way to reach whoever created it. I know there are a million posts on this, but most rely on testing out a bunch of different projected coord. systems after narrowing them down based on the extent. Here's the extent for this data:

TOP: 5058236.102283 | BOTTOM: 4940052.540569 | LEFT: -8264805.988673 | RIGHT: -8180005.401691

From the above, I guess it'd be a UTM projection (?), but I'm not sure what to do about those negative numbers.

I also have partial address info and geocoded one to try to troubleshoot:

XY geocoded: 40.7218342,-73.9787655

UTM based on that lat/long (easting/northing): 586248.1, 4508380.2

What I have in the data for that point (x/y): -8235276.4, 4971409.736

Nothing I've tried comes even remotely close.

Any ideas?

EDIT: Have an idea what these numbers are (if not a solution). I gave up on the shapefile above with the wacky XY coordinates and switched to a different shapefile, which had most of the same points but with a projection specified (NAD_1983_UTM_Zone_18N) and added it to a map that was projected using WGS_1984_Web_Mercator_Auxiliary_Sphere. Later, I was using the "Move to" tool on a point and noted that the pre-populated values in the tool window were in the same wacky coordinates as the other shapefile. E.g. for the above example, it gave me: -8235272.518, 4971391.237. My idea is that these are the transformed XY values resulting from the on-the-fly projection, and that the original data somehow had these also. Maybe it's decimal degrees converted to meters, but relative to the meridian/parallel of the data frame coordinate sys. That said, I'm not sure what they represent or how to transform them back for use in other maps.

s_bklyn
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    Where did your data come from? – Get Spatial Mar 28 '17 at 21:09
  • Based on the coordinates, I'm guessing they are in a State Plane Coordinate system in Feet. Those usually are all positive coordinates, so I wonder if these are in a coordinate system that is centered further east, thus giving you negative X coordinates. – Get Spatial Mar 28 '17 at 21:11
  • Does the shapefile have any metadata? Guessing is not a good idea as there are so many datum/projection/unit combinations but if it's your only hope... start by measuring something you know the distance for to determine if the units are feet or metres, once that is known try the common ones then for adjacent areas.. I have seen negative coords in projected data when the adjacent zone is used. Don't forget Lamberts and Albers projections, there's a few common ones there. If you're really stumped use the spatial adjustment toolbar to warp the data to where you want it to be. – Michael Stimson Mar 28 '17 at 22:52
  • Thanks, Get Spatial. I have an older version of the same data that was a state plane coordinate system, so that may be it, even though these values are dramatically different. This file is a CSV. No metadata. – s_bklyn Mar 28 '17 at 23:17
  • Michael Miles-Stimson, I'll give that a shot (the measuring). I've started trying some math to try to come up with a guess for an adjacent zone. Perhaps I'll see that through. And thanks for the tip on those other projections. – s_bklyn Mar 28 '17 at 23:22
  • The duplicate is for a shapefile when you have X,Y coords, but they can be easily converted to a shapefile, and then used to determine its coordinate system. – PolyGeo Mar 30 '17 at 09:30
  • Thanks for trying to direct over to that other post, PolyGeo. I did go through that post in detail before posting my question. The real issue, as stated in my Q, was that the extent and sample XY were (to me at least) unrecognizable, so it was impossible to "guess" the right projection. I tried a number of the tools and methods (those I could understand) and read all the linked articles. However, I may have stumbled upon a clue, which is pretty different from the the other question. Will edit the Q. – s_bklyn Mar 31 '17 at 20:06

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