The new Commission is derived mainly from the existing Section III (Determination of the Gravity Field), with elements of Sections II, IV and V. In fact mapping the old to the new structure, one can argue that the new Commission 2 should consist of all of existing Section III, Special Commission 7 (Satellite Gravity Field Missions) from Section II, Special Commission 1 (Physical Foundations of Geodesy) with Sub-commission 3 (Boundary Value Problems) from Section IV, and even part of Comission 5 (Earth Tides) from Section V. Of course the latter can fit as well under the new Commission 3 (Earth Rotation and Geodynamics).

Although the theoretical aspects of SC1 and its sub-commission 3 could be covered under the proposed Inter-commission Committee on Theory, it is felt that their natural place is under the new Commission 2, with full cooperation and coordination with the activities of the Inter-Commission Committee.

Then the five major thematic areas of the new Commission 2 will be:

• Gravimetry and Gravity Networks
• Precise Geoid Determination
• Gravity Field Determination from Satellite Altimetry
• Dedicated Gravity Satellite Missions
• Temporal variations of the Gravity Field

Based on the above themes. there are probably only three major elements that will define the structure of Commission 2. In terms of Sub-commissions, these are:

• Sub-commission 1 on Gravimetry and Gravity Networks
• Sub-commission 2 on Spatial and Temporal Modelling of the Gravity Field
• Sub-commission 3 on Dedicated Gravity Satellite Missions

The Proposed SC3 can be part of SC1 or SC2 but, given the very high importance of the new satellite missions, it is felt that, at least initially, this should be a separate sub-commission to deal with the special issues and the variety of applications of these missions. Several study groups similar to the ones that exist currently would again be established to (i) investigate more specific topics and (ii) coordinate regional efforts of gravity mapping, geoid determination, vertical datums, etc.

Commission 2 has very strong links to the newly established International Gravity Field Service (IGFS). IGFS consists of:

IGFS’s terms of reference are avilable under a separate document. It is clear that the givenning bodies of Commission 2 and IGFS should have a few common members on their Boards to ensure constant communication and proper coordination of their activities.