12.540 Principles of the global Positioning System Lecture 15 Prof. Thomas Herring 0409/03 12540Lec15 Propagation Medium: Neutral atmosphere Summary Basic structure of the atmosphere: Here we exclude the effects of electrons in the ionosphere(covered next lecture) Refractivity of constituents in the atmosphere Separation of atmospheric delay into "hydrostatic and wet components Elevation angle dependence Azimuthally symmetric mapping functions Gradient formulations Effects of atmospheric delays on position estimates 12540Lec1504/09/03 12.540 Lec 15 1 12.540 Principles of the Global Positioning System Lecture 15 Prof. Thomas Herring Propagation Medium: Neutral atmosphere • Summary – Basic structure of the atmosphere: Here we exclude the effects of electrons in the ionosphere (covered next lecture). – Refractivity of constituents in the atmosphere – Separation of atmospheric delay into “hydrostatic” and wet components. – Elevation angle dependence: • Azimuthally symmetric mapping functions • Gradient formulations – Effects of atmospheric delays on position estimates 04/09/03 12.540 Lec 15 2 1