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This is a point in Brewster, MA, USA. How would it be converted to WKID 4326?

324299.3348436486, 832511.5939650714

Seibar
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    WGS84 is a datum, not a coordinate system. Your question needs clarification since it doesn't inherently make sense. What is the source of these coordinates? They appear to be easting and northings (presumably in meters), but they don't represent any known location. – Radar Aug 05 '11 at 18:16
  • Is there no projection assigned to the data? Your question needs more clarity / detail (as Radar stated). You should just be able to right mouse on it and check this under the coordinate system tab (assuming your using ArcMap, which you've not stated either). If not, look in the metadata for info, and if that doesn't work, try Googling the name of the shapefile (including the extension [.shp]). – Dano Aug 05 '11 at 18:22
  • See this thread for more information: http://gis.stackexchange.com/questions/664/whats-the-difference-between-a-projection-and-a-datum – Radar Aug 05 '11 at 18:23
  • Thank you for your comment. Is the question clarified if I edit it to request a conversion to WKID 4326? – Seibar Aug 05 '11 at 18:23
  • Where did you get the point coordinates from? – Sasa Ivetic Aug 05 '11 at 18:37
  • This point is from a Brewster, MA government computer system that I do not control and have very little information about. – Seibar Aug 05 '11 at 18:44

2 Answers2

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The coordinates appear to be in NAD 1983 State Plane Massachusetts (Mainland), in meters. I decided this by first adding state and county boundary data to ArcMap. They are in NAD 1983. I then checked on the location of Brewster (southeastern coast of Cape Code Bay). I then set ArcMap's data frame's coordinate system to NAD 1983 State Plane MA mainland zone and looked to see where the coordinates in the question are. They showed up in the Brewster area.

Why did I choose this one first? Coordinates weren't UTM, so probably State Plane. More likely to be NAD83 than NAD27. The values didn't seem big enough to be feet, so tried the meters one.

To answer your question on converting to WGS84 (EPSG:4326), it will depend on what software you have available.

mkennedy
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    +1 This answer is valuable for the insight it provides about how to think about common projections and how to reason about problems like this, which are common. – whuber Aug 05 '11 at 20:35
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I think you're looking for EPSG:26986. Source: http://www.mass.gov/mgis/dd-over.htm

Projecting your point from 26986 -> 4326 you end up in Brewster, MA: 26986->4326 using spatialreference.org

Results in -70.005868000000007, 41.733080999999999 -> Google Maps

Sasa Ivetic
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  • Thanks. I can confirm that this is correct based on the address that I have for this point. – Seibar Aug 05 '11 at 19:02