Jackson County has an adjusted version of the WISCRS projection that has been in use since 2011. The definitions for the adjusted WISCRS projection and the official WISCRS projection (published in SCO’s “Wisconsin Coordinate Reference Systems” handbook) are very similar. Differences are highlighted in red.
| Adjusted Projection [1] | Official Projection [2] | |
|---|---|---|
| Base Reference System | NAD 83 (2011) | NAD 83 (1991) |
| Projection Type | Transverse Mercator | Transverse Mercator |
| False Northing | 82,020.833 ft (U.S. Survey Foot) | 25,000.0000 m or 82,020.833 ft (U.S. Survey Foot) |
| False Easting | 88,582.5 ft (U.S. Survey Foot) | 27,000.0000 m or 88,582.500 ft (U.S. Survey Foot) |
| Latitude of Origin | 44° 15′ 12.00716″ N | 44° 15′ 12.006460″ N |
| Central Meridian/Longitude of Origin | 90° 50′ 39.46745″ W | 90° 50′ 39.467470″ W |
| Scale Factor | 1.0000353 | 1.0000353000 |
| Units | U.S. Survey Feet | Meters or U.S. Survey Feet |
[1] Source for Adjusted Projection parameters.
[2] Source for Official Projection parameters.
The adjusted projection allows WISCORS (CORS network) coordinates (latitude-longitude) based on NAD 83 (2011) to be used to produce projected coordinates that approximate the official WISCRS projection for NAD 83 (1991).
Official projection: NAD 83 (1991) coordinates (latitude-longitude) –> Official projection –> Jackson County WISCRS coordinates (eastings, northings), NAD 83 (1991)
Adjusted Projection: NAD 83 (2011) coordinates (latitude-longitude) –> Adjusted projection –> Coordinates approximately equal to Jackson County WISCRS (eastings, northings), NAD 83 (1991)
Although the adjusted projection uses NAD 83 (2011) coordinates, the intent of the projection is Jackson County WISCRS for NAD 83 (1991), not NAD 83 (2011).
The coordinate differences between NAD 83 (1991) and (2011) are fairly small, on the order of a few centimeters. This may be below the threshold of concern for many GIS users.
Users should be aware that data from Jackson County may be in the adjusted projection. The projection should be recognized in ArcGIS Pro Ver 3.3.1 and later.
For more information about Jackson County’s Adjusted Projection, contact Cody Brommerich, PLS, CFedS, County Surveyor, 307 Main St., Black River Falls, WI 54615. Phone: 715-284-0221