Figuring out Map Projection for X, Y Coordinates

[JohnHandley]

I have coordinates that someone sent me and I'm having a problem figuring out the corresponding Map Projection. Normally I can solve these issues, but this one has stumped.

X 2,212,050., Y 11,298,265. West Texas, Pecos County (Numbers have been tweaked to protect the innocent.)

Thanks

[AbdullahAnter]

Is the coordinates for only point? or you have many coordinates ?

Do you know where the coordinates locate?

[JohnHandley]

Coordinates are for one point. Located in Pecos County, Texas (USA). Thanks

John R. Handley

Sr. GIS Technician – System Planning

(Work) 713-989-2033

(Cell) 832-229-2093

[DanPatterson_Retired]

Well could be UTM or one of your state plane coordinates (probably in feet) since you are about 11,300,00 feet from the equator.  It can't be meters since there are only about 10,000,000 meters from the equator to the poles.  Now since you are the GIS technician, presumably there, why not look for what other data is around that you can align it with and try a projected coordinate system, for that area.  You will either be bang on, or way off.... because you can't tell were something is from 2 numbers.  For example, there are 120 places on earth with the exact same UTM coordinates, they differ by their UTM zone (60) and whether they are north or south of the equator.  At least you have narrowed it down

[MelitaKennedy]

Add the data (still with unknown/undefined coordinate system) to ArcMap. Add some base data that you know has a good coordinate system. Set the data frame's coordinate system to various "candidate" coordinate systems, like Texas state systems, state plane, etc. The base data will be projected to the new coordinate system. If the base data overlays the "unknown" data, you've found the coordinate system.

Neither of those works, by the way, but I think it might be what we call BLM zone 12N (US feet). It could be based on NAD27 or NAD83.

Projected coordinate systems, UTM, BLM (US Feet)

Melita

[JohnHandley · Accepted solution]

Bingo! It is UTM Zone 13 N in Feet.

I’m so use to working with UTM Meters , I had a mental block. Thanks

John R. Handley

Sr. GIS Technician – System Planning

(Work) 713-989-2033

(Cell) 832-229-2093