Primary research programs Geophysical research GPS analysis packages GAMIT (GPS at MIT): Uses double differences GYPSY: Jet Propulsion Laboratory (JPL) processing packages: Uses one-way observables and explicitly estimates clocks Bernese: Developed at Astronomical Institute University of Bern, Switzerland. Also referred to as BPE ( Bernese Processing Engine). Double differences Files needed for precise geodesy For all programs the basic class of files needed to accurately compute the apriori models of the delays and phas Table of satellite types. Since the PRn numbers are re-used (1-32), there could be ambiguity about the mass, size and hase center position of the satellites. There is a unique sv number for each satellite. Latest is 54 Ephemeredes of Sun and Moon. Needed for tidal forces or satellite. Can be in tabular form(most common; Harvard Smithsonian Center for Astrophysics and JPL produce these) or in analytic form(accuracy problems ). Ephemeredes can also be used for eart04/30/03 12.540 Lec 20 3 Primary research programs packages: – – GYPSY: Jet Propulsion Laboratory (JPL) and explicitly estimates clocks – University of Bern, Switzerland. Also referred to as BPE (Bernese Processing Engine). Double differences. 04/30/03 12.540 Lec 20 4 Files needed for precise geodesy • For all programs the basic class of files needed to accurately compute the apriori models of the delays and phase: Since the PRN numbers are re-used (1-32), there could be ambiguity about the mass, size and phase center position of the satellites. There is a unique SV number for each satellite. Latest is 54. Needed for tidal forces on satellite. Smithsonian Center for Astrophysics and JPL produce these) or in analytic form (accuracy problems). Ephemeredes can also be used for Earth tide calculations. • Geophysical research GPS analysis GAMIT (GPS at MIT): Uses double differences processing packages: Uses one-way observables Bernese: Developed at Astronomical Institute – Table of satellite types. – Ephemeredes of Sun and Moon. Can be in tabular form (most common; Harvard- 2