1. A method for satellite navigation, comprising: acquiring, by a communication device, broadcast ephemeris from a satellite signal during a data refresh operation; computing, by the communication device, extended ephemeris from the acquired broadcast ephemeris during the data refresh operation; determining, by the communication device, satellite navigation information from the computed extended ephemeris during a positioning operation that is different from the data refresh operation and subsequent to the data refresh operation; and dynamically modifying, by the communication device, a time associated with a schedule of the data refresh operation based on the computed extended ephemeris.