[GIS] Lat Long to State Plane conversion

arcgis-javascript-apiarcgis-rest-apiconvertlatitude longitudestate-plane

I am using the ESRI javascript API and I have a set of lat/long points I need to convert to a state plane coordinate system. My spatial reference is wkid 3418.

I can easily use the GeometryService to project the state plane to lat/long, but need to go in the opposite direction.

I was looking at the REST API for ArcGIS and saw a setting transformFoward. Is this the setting I need to go in that direction? (http://resources.arcgis.com/en/help/arcgis-rest-api/index.html#//02r3000000pv000000)

What are ways I can do this conversion?

Best Answer

You shouldn't need to specify transformForward. Just set the inSR to 4269 (from Geographic Coordinate Systems, for GCS_North_American_1983), and the outSR parameter to 3418.

Related Solutions

[GIS] Why is the longitude conversion from NY State Plane Coordinate System to WGS84 consistently off by 3.665 degrees

I'm going to go out on a limb and say that you aren't including the False Easting and False Northing in your XY coordinates. EPSG:4456 states the FE and FN values should be 2000000 and 100000 respectively. Being short 2 million feet on the easting value would explain why your point is in Pennsylvania.

If you change your point to include these values (x=2982394 y=299298) then that looks like the location you might be expecting.

EDIT -- I just checked earthpoint.us and WGS84 is the datum they are basing the calculation on. There is no State Plane Zone based on WGS84, so they're probably using the NAD83 parameters. For NAD83 NY/Long Island, the False Easting/Northing values are 984250/0 respectively. Try changing your output EPSG code to 2263 and see if that fixes the issue.

SIDE NOTE! If you are 100% positive that your data is in NAD27, then it's possible the wrong FE/FN values have been applied to your data.

[GIS] Formula to convert State Plane Coordinates to Latitude and Longitude

If you set the "Output spatial reference" field to "4326", you'll get the results returned using EPSG:4326 coordinate system, which is the usual lat-long used these days, and is the same system that most GPS units default to.

With "output spatial reference" left blank:

# results: 1

OwnerName:  US GOVERNMENT
geometry    Polygon:
Ring0:[981499.81518554687,197022.05780029297],[981381.22521972656,196861.61462402344],[981307.0732421875,196922.38079833984]...2 more...

With "output spatial reference" set to 4326:

# results: 1

OwnerName:  US GOVERNMENT
geometry    Polygon:
Ring0:[-74.009920968454054,40.707464582669736],[-74.010348637064965,40.7070241663017],[-74.010616117411985,40.707190930767545]...2 more...

Best Answer

Related Solutions

[GIS] Why is the longitude conversion from NY State Plane Coordinate System to WGS84 consistently off by 3.665 degrees

[GIS] Formula to convert State Plane Coordinates to Latitude and Longitude

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