FIG Commission 5

Working Group 5.2 - Reference Frame in Practice

About This Working Group

The FIG Working Group 5.2 (Reference Frame in Practice) was initially created at the FIG Congress in Brighton in 1998 and reorganised at the FIG Congresses in Washington 2002 and in Munich 2006. Its work plan and mission is described below. In short terms, the working group will try to summarize important questions for the surveyor regarding reference frame issues. This is done at this webpage by gathering technical manuals, fact sheets, links etc. and can be seen more as internet portal for information. Among the links we have also gathered links to national agencies that are responsible for national transformation formulae etc.

The proposed Chair of the working group is:

Mikael Lilje (Sweden),
Geodetic Research Division
SE-802 81 GÄVLE

The Core Members for the period 2002-2006 were besides the chair also:

Their participation for the period 2006-2010 needs to be confirmed.

Beside the core members group, there were a reference member group. The members were :

  • Bengt Eurenius (Sweden)
  • Francoise Duquenne (France)
  • Per-Ola Eriksson (Sweden)
  • Vladimir Sedlak (Slovakia)
  • Graeme Blick (New Zealand)
  • Matt Higgins (Australia)
  • Ales Cepek (Czech Republic)

Anyone can be a member of the working group. If you are interested to contribute, please send an email to Mikael Lilje or Rob Sarib.

The working group meets specifically during FIG events as the FIG Working Weeks. At these events the working group tries to organise special sessions concerning the subject. The working group also tries to develop or search the Internet for Technical Fact Sheets as outlined above.

Work Plan

Policy Issues

  • Work to bring together all organisations involved in defining or using reference frames to develop common approaches and avoid duplication. Such organisations include FIG, the International Association of Geodesy (IAG), ISO, groups of national mapping agencies, other influential national agencies (such as the US Department of Defence’s National Geospatial-Intelligence Agency (NGA), which is responsible for WGS84.) and alliances of commercial organisations (such as Open GIS Consortium and the European Petroleum Survey Group).
  • Continue the existing co-operation with IAG on the African Reference Frame Project (AFREF) as well as facilitate similar actions on other continents such as South America and Asia
  • Provide background technical information on relevant issues written in a way that is accessible to the surveying practitioners.
  • Develop an inventory of approaches to reference frame issues in different countries (including transformation methodologies) that is accessible to surveying practitioners
  • Examine the concepts of dynamic and semi-dynamic datums.
  • Examine how surveying practitioners are changing how they access the reference frame, through less emphasis on networks of ground monuments and more emphasis on Global Navigation Satellite Systems (GNSS) base stations.
  • Examine global positioning services such as OmniSTAR and StarFire and their use for positioning in a national reference frame 
  • Examine the increased use of GNSS for height determination and the use of geoid models etc for connection to local height datums.
  • Examine the role that the satellite missions GRACE, GOCE and CHAMP will have on global geoid models
  • Examine the increasing role of aerial and space based imagery in the realisation of reference frames.
  • Liaise with Commission 4 to review and revise (where required) FIG Publication 37, Vertical Reference Surface for Hydrography

Mikael Lilje (Sweden), e-mail:

Specific project(s)

  • Initiate, contribute and facilitate meeting(s) of all organisations involved in defining or using (regional) reference frames to develop common approaches and avoid duplication.
  • Continue development of Technical Fact Sheets that briefly explain basic concepts, practical applications and issues and which summarise the activities of organisations with specific responsibilities in the field.
  • Ensure terminology used in above publications conform to and give substance to the relevant Standards coming from ISO TC211.
  • Ensure that the working group web page is running and updated.


  • Participation in FIG Working Weeks and other major Commission events (see events section below) with dedicated Technical Sessions and/or Workshops as appropriate.
  • Seminars and meetings involving key organisations involved in defining or using (regional) reference frames will be convened at a venue, time and date to be confirmed by the Working Group Chairs.
  • Symposium on Applications of Permanent GPS/GNSS Networks. WG 5.2 and WG 5.3 event.


  • Web page
  • FIG Working Weeks will include Technical Papers on specific issues and presented by Working Group Members and other invited experts.
  • Technical Fact Sheets as outlined above.
  • Working group final report will be presented at FIG Congress, 2010.

Time table

  • Draft publications will be presented at FIG Working Weeks during the term of this plan and according to a timetable to be developed by the Working Group Chairs.
  • Working group final report: dedicated session, FIG Congress, 2010.