Co-Chairs: Michael Craymer (Canada)

Vice-Chair: Dan Roman (USA) 

 

Terms of Reference

To provide international focus and cooperation for issues involving the horizontal, vertical, and three-dimensional geodetic control networks of North America, including Central America, the Caribbean and Greenland (Denmark). For more information, see www.naref.org.

 

Objectives

In collaboration with the IAG community, its service organisations and the national geodetic organizations of North America, the aims and objectives of this regional Sub-commission are to provide international focus and cooperation for issues involving the horizontal, vertical and three dimensional geodetic control networks of North America. Some of these issues include:

  • Densification of the ITRF reference frame in North America and the promotion of its use;
  • Maintenance and future evolution of plate-fixed geometric reference frames for North America, including the North American Datum of 1983 (NAD83) and any possible successors.
  • Maintenance and future evolution of vertical datums (ellipsoidal and orthometric), including the North American Vertical Datum of 1988 (NAVD88) and the International Great Lakes Datum (IGLD);
  • Effects of crustal motion, including post-glacial rebound and tectonic motions along, e.g., the western coast of North America and in the Caribbean;
  • Standards for the accuracy of geodetic positions;
  • Outreach to the general public through focused symposia, articles, workshops and lectures, and technology transfer to other groups.

 

Structure

  • Chairs: Michael Craymer (Canada)
  • Vice-Chair: Dan Roman (USA)
  • WG organizing committee
    • Members: Michael Craymer (Canada), Dan Roman (USA), Bo Finn Madsen (Denmark), Guido Gonzalez (Mexico)

Working Groups

  • SC1.3c-WG1: North American Reference Frame (NAREF)
    • Chair: Michael Craymer (Canada)
  • SC1.3c-WG2: Plate-Fixed North American Reference Frame
    • Chair: TBD (USA)
  • SC1.3c-WG3: Reference Frame Transformations
    • Chair: Michael Craymer (Canada)

Programme of Activities

  • SC1.3c-WG1 – North American Reference Frame (NAREF): To densify the ITRF reference frame in the North American region by organizing the computation of weekly coordinate solutions and associated accuracy information for continuously operating GPS stations that are not part of the current IGS global network. A cumulative solution of coordinate and velocities will also be determined on a weekly basis. The working group will organize, collect, analyse and combine solutions from individual agencies, and archive and disseminate the weekly and cumulative solutions.
  • SC1.3c-WG2 – Plate-Fixed North American Reference Frame: To establish a high-accuracy, geocentric reference frame, including velocity models, procedures and transformations, tied to the stable part of the North American tectonic plate which would replace NAD83 and serve the broad scientific and geomatics communities by providing a consistent, mm-accuracy, stable reference with which scientific and geomatics results (e.g., positioning in tectonically active areas) can be produced and compared.
  • SC1.3c-WG3 – Reference Frame Transformations in North America: To determine consistent relationships between international, regional and national reference frames/datums in North America, to maintain (update) these relationships as needed and to provide tools for implementing these relationships.