Orbit Information and SA Technology Orbit Inf and sa: o The activation of sa in the block ii satellites may lead to a degradation of the broadcast orbit up to 50-100m Civil Community Since some users need more precise ephemerides, the civil community must generate its own precise satellite ephemerides 電 Principles of the Global Positioning System 2005-3-11(7 Orbit Description Principles of the Global Positioning System 2005-3-11(84 Principles of the Global Positioning System 2005-3-11 7 Orbit Inf. and SA: ‹ The activation of SA in the Block II satellites may lead to a degradation of the broadcast orbit up to 50-100 m. Civil Community: ‹ Since some users need more precise ephemerides, the civil community must generate its own precise satellite ephemerides. Orbit Information and SA Technology Principles of the Global Positioning System 2005-3-11 8 Orbit Description