In late December 2015, we announced the Wisconsin Coordinate Reference Systems (WISCRS) used by cities and counties in the state were added to the International Association of Oil & Gas Producers (IOGP) Geodetic Parameter Dataset.
This action made it possible for software companies and GIS users or developers to utilize WISCRS by inserting EPSG codes in their applications, rather than typing in coordinate system parameters by hand.
The 2015 edition included WISCRS parameters referenced to the NAD83 (2011) datum only. Our rationale at that time was coordinate differences between NAD83 “HARN” (a.k.a, NAD83/91) and NAD83 (2011) were trivial for most GIS applications. After receiving feedback from the community and software companies, earlier this spring we initiated a second “change request” to add WISCRS referenced to the NAD83 HARN datum to the Geodetic Parameter Dataset.*
The IOGP published their latest update last week, which now includes four versions of WISCRS for each of the 59 zones in the state (some counties share a common set of parameters):
NAD83(2011) WISCRS – US Survey Foot
NAD83(2011) WISCRS – Meters
NAD83(HARN) WISCRS – US Survey Foot
NAD83(HARN) WISCRS – Meters
If you have any questions about the new EPSG codes, or WISCRS in general, feel free to contact me at (608) 262-6850.
* Note: An earlier version of this article could be interpreted to mean that new parameters (central meridian, false easting/northing, etc.) were developed to support NAD83 HARN or NAD83 (2011). That is not the case. The specific parameters for WISCRS remain unchanged, regardless of the datum adjustment used. The recent update to the EPSG database simply creates additional references to WISCRS that utilize the NAD83 HARN datum adjustment.