Celestial Sphere : An imaginary sphere of infinite radius concentric with the Earth on which all celestial bodies except the Earth are imagined to be projected
National Oceanic and Atmospheric Administration NOAA, Tide and Current Glossary, National Ocean Service, CO-OPS, Products and Services N/OPS3, Silver Spring, MD, USA 1999. http://co-ops.nos.noaa.gov/publications/glossary2. pdf, (ND/ Tide and Current - Amer) {830}
