Terms of Reference and Objectives

The primary objective of the Project is the development of a geoid model for North America and surrounding oceans in order to achieve a common vertical datum. Its development will require the determination of the gravity field for an area encompassing Iceland, Greenland, Canada, USA (including Alaska and Hawaii), Mexico and countries forming Central America and the Caribbean Sea, referred to herein as "North America". The geoid model for North America could be used as the common datum to relate national datums or tailored using; for example, "GPS/Leveling" in order to depict the official national vertical datum as it is done in Canada and USA. The achievement of a geoid model for North America will be accomplished by coordinating activities between agencies and universities with interest in geoid theory, gravity, digital elevation models (DEM), topographical density, altimetry, sea surface topography, leveling and vertical datum.

The determination of a geoid model for North America is not limited to a single agency, which will collect all necessary data from all countries. The Project encourages theoretical diversity in the determination of a geoid model between the agencies. Each agency takes responsibility or works in collaboration with neighboring countries in the development of a geoid model for their respective country with an overlap (as large as possible) over adjacent countries. Each solution will be compared, the discrepancies will be analyzed, and the conclusions will be used to improve on the next model. Thus, the geoid model for North America will be derived from a "mosaic" of geoid model

The chair of the Project will meet with the equivalent European and South American projects to discuss overlap regions and to work towards agreements to exchange data. Finally, the members of the Project will keep close contact with all related Study Groups of the IAG. The Project is open to all geodetic agencies and universities across North America with an interest in the development of a geoid model for North America. The meetings of the Commission Project 2.2 are open to everyone with interests in geodesy, geophysics, oceanography and other related topics. A list of members is available on the web site of the North American geoid project:

www.geod.nrcan.gc.ca/~marc/Html/GGSCNA/GGSCNA.html.
(Username: marc password: private)

Members will communicate primarily using e-mails. However, members of the Project plan to arrange annual meetings. Preferably, these meetings will be held during international conferences where most members will be present; however, some meetings will be held in North America to minimize travel costs. Minutes of meeting will be prepared and sent to all members of the Project.s.

This Commission Project reports to Sub-Commission 2.4