Galileo orbit determination from launch through the first earth flyby

The data types used in the Galileo orbit determination process and the primary effects on the spacecraft for the first two trajectory legs of the mission are discussed. These types are: two-way coherent Doppler, two-way range, and delta differential one-way range. Attention is given to four primary nongravitational accelerations that affect the Galileo spacecraft: Delta(V) from TCMs, the Delta(V) from attitude updates, the Delta(V) from thruster maintenance events, and solar radiation pressure.