A method for estimating the position of an object by a location-determining receiver associated with the object, the method comprising the steps of: - measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by the location-determining receiver , - estimating a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase by a primary real time kinematic engine , - determining if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period based on one or more reliability tests applied to a quadratic form of carrier phase residuals, - estimating a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase by a secondary real time kinematic engine during a later period following the earlier evaluation period; - where the states of an error reducing filter , the first real time kinematic engine and the second real time kinematic engine are corrupt or inaccurate, reinitializing both real time kinematic engines in a time offset manner to provide enhanced reliability afforded by different start-up times of the real time kinematic engines ; - determining if the secondary real time kinematic engine is searching for a solution of the estimated secondary integer ambiguity for longer than a maximum threshold time during later evaluation period, - and resetting the secondary real time kinematic engine if the secondary real time kinematic engine is searching for the estimated secondary integer ambiguity for longer than a maximum threshold time, and using the primary real time kinematic engine during the resetting process. - measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by the location-determining receiver , - estimating a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase by a primary real time kinematic engine , - determining if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period based on one or more reliability tests applied to a quadratic form of carrier phase residuals, - estimating a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase by a secondary real time kinematic engine during a later period following the earlier evaluation period; - where the states of an error reducing filter , the first real time kinematic engine and the second real time kinematic engine are corrupt or inaccurate, reinitializing both real time kinematic engines in a time offset manner to provide enhanced reliability afforded by different start-up times of the real time kinematic engines ; - determining if the secondary real time kinematic engine is searching for a solution of the estimated secondary integer ambiguity for longer than a maximum threshold time during later evaluation period, - and resetting the secondary real time kinematic engine if the secondary real time kinematic engine is searching for the estimated secondary integer ambiguity for longer than a maximum threshold time, and using the primary real time kinematic engine during the resetting process. <EOS>