A navigation receiver operating in a differential navigation mode transmits primary estimates of coordinates with an accuracy estimate that can vary during operation. To improve the positioning quality when the accuracy estimate changes, smoothed estimates of coordinates are generated according to a two-branch algorithm. The current-epoch accuracy estimate is compared to a current-epoch value of threshold accuracy. Upon determining that the current-epoch accuracy estimate is greater than or equal to the current-epoch value of threshold accuracy, the current-epoch smoothed estimates of coordinates are set equal to the current-epoch extended estimates of coordinates calculated from the sum of the previous smoothed estimates of coordinates and coordinate increments calculated from carrier phases. Upon determining that the current-epoch accuracy estimate is less than the current-epoch value of threshold accuracy, the current-epoch smoothed estimates of coordinates are generated based on the sum of the current-epoch extended estimates of coordinates and a correction signal.