A method of determining satellite clock corrections to allow at least one location-determining receiver to provide at least one of a position estimate or a velocity estimate or a time estimate, the method comprising: collecting pseudo-range code measurements, carrier-phase measurements, and broadcast satellite clock errors from a network of stationary receivers of satellite signals transmitted by one or more constellations of navigation satellites, whereby the broadcast satellite clock errors are broadcast from the respective satellite; at each epoch, computing a computed satellite clock error for each navigation satellite based on the pseudo-range code measurements, the carrier phase measurements, the respective known locations of the stationary receivers and the broadcast satellite clock errors; characterized by: forming clock error differences between corresponding pairs of the computed satellite clock error and a broadcast satellite clock error for each navigation satellite; for each constellation, selecting a clock reference satellite, from among the navigation satellites in that constellation, that has a median value of the clock error differences for that satellite constellation; and computing a correction to the broadcast clock error of each navigation satellite by adding a function of the clock reference satellite's clock error to the broadcast clock error for each satellite in the one or more constellations, where a value of the correction per epoch or other time interval is limited based on a control parameter limit. collecting pseudo-range code measurements, carrier-phase measurements, and broadcast satellite clock errors from a network of stationary receivers of satellite signals transmitted by one or more constellations of navigation satellites, whereby the broadcast satellite clock errors are broadcast from the respective satellite; at each epoch, computing a computed satellite clock error for each navigation satellite based on the pseudo-range code measurements, the carrier phase measurements, the respective known locations of the stationary receivers and the broadcast satellite clock errors; characterized by: forming clock error differences between corresponding pairs of the computed satellite clock error and a broadcast satellite clock error for each navigation satellite; for each constellation, selecting a clock reference satellite, from among the navigation satellites in that constellation, that has a median value of the clock error differences for that satellite constellation; and computing a correction to the broadcast clock error of each navigation satellite by adding a function of the clock reference satellite's clock error to the broadcast clock error for each satellite in the one or more constellations, where a value of the correction per epoch or other time interval is limited based on a control parameter limit. forming clock error differences between corresponding pairs of the computed satellite clock error and a broadcast satellite clock error for each navigation satellite; for each constellation, selecting a clock reference satellite, from among the navigation satellites in that constellation, that has a median value of the clock error differences for that satellite constellation; and computing a correction to the broadcast clock error of each navigation satellite by adding a function of the clock reference satellite's clock error to the broadcast clock error for each satellite in the one or more constellations, where a value of the correction per epoch or other time interval is limited based on a control parameter limit.