DOMES and DOMEX Procedure

The DOMES numbering system was designed by Claude Boucher (IGN), at the start of the MERIT campaign in early 1980s in order to give an unambiguous identifier to all instrument reference points and markers involved in this MERIT campaign. The first publication of these informations was done in a catalogue published by the Bureau International de l'Heure (BIH) and entitled "Directory Of MERIT Sites", hence DOMES. The BIH, together with the IGN group, was acting as MERIT coordinating center. Since the official start of IERS in 1988, the TRF section of the IERS/CB continued this task for all ITRF contributing stations. The description of the DOMES numbering is as the following (cf. MERIT/COTES Joint Working Groups, MERIT Campaign: Connection of Reference Frames, Implementation Plan, 1983):


  • the first 3 digits indicate the area, usually the country (e.g., 100 France)
  • the next 2 digits designate the site number within the country (e.g., 02 Grasse)
  • the next letter indicates the tracking point (e.g., M or S );
    • M is a monument point such as pillar, pole, brass mark, etc.
    • S indicates the reference point of an instrument such as the
    • intersection of axes of an SLR telescope, reference point
    • of a VLBI antenna, DORIS or GPS Antenna Reference Point (ARP)
  • the last 3 digits represent a sequential point number (e.g., 006 GPS reference Marker)

For a new station, a DOMES number request should be directed to the IERS TRF section (domes @ ign.fr), by filling in a DOMES Information Form (DIF) available at http://itrf.ensg.ign.fr/domes_request.php.

ILRS CB Note: If an existing station's reference point has changed and if the reference point was the marker, then a request for a new Site Occupation Designator and a new DOMES number is required.

The DOMES numbers are assigned and of the responsibility of the IERS TRF section, Laboratoire de Recherche en Geodesie (LAREG), IGN France.

The DOMES numbering system was designed several years ago in the frame of the MERIT project which gave birth to IERS. The continuation of this numbering was ensured by the ITFS of the IERS Central Bureau. As ITRF is more and more widely used, the DOMES system which was designed for a few hundred station capacity has to be abandoned. A new system DOMEX (which holds for DOMEs EXtended) has been defined.

  • 9 characters like DOMES.
  • 6 digits for site id (3 for area, usually country, and 3 for site) + 1 letter M or S like in DOMES + 2 digits for monument or station.
  • in principle we shall use the translation for DOMES into DOMEX according to:
          DOMES 99999L0yy will become DOMEX 999990Lyy.
  • a complete cross table will be available from the IERS

The recommended rules are:

  • for IERS uses, as long as DOMEX is not yet extensively distributed, to use DOMES for existing instruments. The DOMEX system is designed to be able to derive automatically the DOMEX value from the DOMES value.
  • flexibility to use indifferently DOMES or DOMEX in SINEX files: same character length and no possible confusion (one can automatically identify whether it is a DOMES or a DOMEX number!)

IGN:   Institut Geographique National, Paris
MERIT: Monitoring of Earth Rotation and Intercomparison of Techniques
IERS:  International Earth Rotation Service
ITRF:  International Terrestrial Reference Frame
SLR:   Satellite Laser Ranging
VLBI:  Very Long Baseline Interferometry
DORIS: Doppler Orbitography and Radiopositioning Integrated by Satellite