University of Wisconsin–Madison

Wisconsin Geospatial News

WSRS2022 submits letter to NGS requesting policy exceptions

The Wisconsin Spatial Reference System 2022 Task Force (WSRS2022) has submitted a letter to the National Geodetic Survey (NGS) requesting specific exceptions to NGS’s policy regarding the modernization of the State Plane Coordinate System (SPCS) associated with the introduction of a new terrestrial reference frame in 2022.

This letter is consistent with an earlier (August 17, 2018) letter to the NGS in reponse to Federal Register Notice 83 FR 17149 requesting feedback on the NGS’s draft policy for SPCS2022.

The most recent letter seeks exceptions to NGS policy regarding low-distortion projections (LDPs), specifically:

  1. SPCS2022 Policy 2.a. stating that only one multi-zone layer can provide complete coverage of an entire state.
  2. NGS specifications that conflict with plans for WISCRS, Wisconsin’s LDP system.
  3. The requirement for completion of the online design submittal form to describe exceptions in detail.

The letter makes the case that these exceptions are in the mutual interests of both NGS and the State of Wisconsin.

The technical content of the letter was drafted primarily by the WSRS2022’s Technical Focus Group, with discussion and consensus arrived at by the entire Task Force at a series of quarterly meetings. The letter was approved at the August 8 meeting in Madison.

The letter also addresses the question of a single-zone statewide layer and a three-zone layer covering the state, which are also covered by NGS’s SPCS policy. The letter states that Wisconsin will request:

  1. That NGS design a statewide single-zone layer which is a Transverse Mercator projection with its central meridian at 270° east longitude and has a false easting significantly different from those of WTM 27 and WTM 83. (WTM is the Wisconsin Transverse Mercator reference system.)
  2. That NGS design a default three-zone layer for Wisconsin that will consist of three Lambert Conformal Conic zones with boundaries identical to those of SPCS 83.
  3. That if the NGS design must have a central meridian at a longitude other than 270° east, then the longitude difference be taken into account when selecting the false easting to be significantly different from those of WTM 27 and WTM 83 (for the single-zone layer) and those of SPCS 27 and SPCS 83 (for the three-zone layer).

The full text of the letter can be found here.

WSRS2022 was formed in January 2019 under the auspices of the Wisconsin Society of Land Surveyors (WSLS). WSRS2022 represents a broad coalition of geospatial and surveying professionals in Wisconsin, including federal, state, regional, county and local governments, as well as agencies, corporations and associations involved in the production and use of geospatial data. WSRS2022 has five focus groups, each designed to address a specific issue of concern. For more information on WSRS2022 see the Task Force’s web page.

The next WSRS2022 Quarterly Meeting is tentatively planned for Octover 11, 2019, in Rothschild.