1. National Geodetic Survey Charting and Geodetic Services, Rockville, Maryland 20852.
2. National Ocean Service, Rockville, Maryland 20852.
3. National Oceanic and Atmospheric Administration, Rockville, Maryland 20852.
4. Center for Space Research, Department of Aerospace Engineering and Engineering Mechanics, University of Texas, Austin 78712.
5. National Bureau of Surveying and Mapping, Beijing, People's Republic of China.