Patent ID: 8766848
Filing Date: 2014-07-01
Classification: G01S

Abstract:
1. A method for estimating one or more integer ambiguity sets related to estimating the position of an object by a location-determining receiver associated with the object, the method comprising: 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 (RTK) engine; determining if the primary integer ambiguity set is resolved correctly to a predefined reliability rate during an earlier evaluation period based one or more reliability tests applied to a quadratic form of carrier phase residuals; and 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 (RTK) engine during a later period following the earlier evaluation period; establishing a time offset between respective start-up times of the primary RTK engine and the secondary RTK engine to support enhanced reliability by avoiding or reducing corruption from imprecise measurements; resetting ambiguities from the primary RTK engine if they are resolved to different integer values than collectively from both the secondary RTK engine and the primary RTK engine, and reinitializing the secondary RTK engine after a current epoch and continuing to perform the ambiguity resolution until the same integer ambiguity set as the primary RTK engine is achieved.