Large database has x and y coordinates that are unknown to me

[pick44]

I have looked and looked and looked for a conversion for these sample x & y numbers attached. They are locations in McKinney Tx.
Has anyone seen these types before? If so, did you find a way to convert to lat and long?

Thanks

[MrShorty]

Not familiar with this myself, but I put "geox geoy meaning" into my favorite internet search engine, which led me to "state plane coordinate" systems: https://en.wikipedia.org/wiki/State_...rdinate_System
https://www.ngs.noaa.gov/TOOLS/spc.shtml
http://www.earthpoint.us/StatePlane.aspx
http://resources.arcgis.com/en/help/...0043000000.htm

That's as far as I went with it. Is that a possibility?

[pick44]

I tried the ones you showed but could not get any to work. However, I did find one coordinate that I pulled from an address and then used Google Earth to find the lat and long. Here is what I did find.

Geox Geoy Lat Long
253704650 713336950 33.22873 96.6400782

[MrShorty]

I'm not sure what to recommend, as I am not familiar with these different geographic coordinate systems. I don't know if anyone on this forum dabbles in this kind of stuff. If not, it may be preferable to talk to someone who is familiar with the different geographic coordinate system used in Texas.

[pick44]

Yes, I will do that. I have sent an email to the Civil Engineering Dept of the city and ask for their help.

thanks again, blessings, ><>

[Aardigspook]

They look like some sort of UTM coordinates. If that's the case, you'll need to find out what UTM zone they are from.
From https://www.expertgps.com/convert-coordinates.asp:

Universal Transverse Mercator (UTM) coordinates are used worldwide. Unlike lat/lon, which is a spherical coordinate system based on angles, UTM, state plane, and national grid coordinates are rectangular grid systems where coordinates are expressed as Northings and Eastings from a fixed reference point. Rectangular grids make it much easier to calculate distances and to plot locations on a rectangular map. UTM coordinates look like this: 2346212N, 12343523E, 18T. The first value is the Northing. The second is the Easting. The third value (always a number between 1 and 60 followed by a single letter) is the UTM zone identifier. If your data is in UTM coordinates, it is very likely in NAD27 datum or WGS84 datum (see below). The vast majority of UTM data is expressed in meters. If you are using UTM data collected prior to 1983 by a US state entity, there's a chance that it uses US Survey Feet rather than meters as the base unit.

If you can't find the zone, it might be possible to work backwards to get the reference point by taking known points and comparing their geox/geoy with Lat/Long - but it would not be quick or simple.

[pick44]

Found the answer. The numbers should look like this:
2537046.50 7133369.50

The last two numbers should have a leading "."
This is the NAD 83, 4202 NORTH CENTRAL TEXAS AREA.