Method and system for estimating position with bias compensation

A method for estimating the position of an object by a location-determining receiver associated with the object, the method comprising:

• measuring a first carrier phase of each first carrier signal of a plurality of first carrier signals and a second carrier phase of each second carrier signal of a plurality of second carrier signals received by the location-determining receiver, each first carrier signal of the plurality of first carrier signals received at substantially the same frequency as others of the first carrier signals from two or more primary satellites, each second carrier signal of the plurality of second carrier signals being received at substantially the same frequency as others of the second carrier signals from two or more primary satellites;
• measuring a third carrier phase of each third carrier signal of a plurality of third carrier signals and a fourth carrier phase of each fourth carrier of a plurality of fourth carrier signals signal received by the location-determining receiver, each third carrier signal of the plurality of third carrier signals being transmitted at different frequencies from others of third carrier signals from two or more secondary satellites, each fourth carrier signal of the plurality of fourth carrier signals being transmitted at different frequencies from others of the plurality of fourth carrier signals from two or more secondary satellites that results in an inter-channel bias between carrier signals from different ones of the secondary satellites observable at the location-determining receiver;
• estimating a first integer ambiguity set associated with the measured first carrier phase, and a second integer ambiguity set associated with the measured second carrier phase;
• estimating a third ambiguity set associated with the measured third carrier phase and a fourth ambiguity set associated with the measured fourth carrier phase by calculating the double difference ambiguity set associated with third carrier signals from different secondary satellites, and calculating the double difference ambiguity set associated with fourth carrier signals from different secondary satellites;
• compensating for the inter-channel bias in at least one of the third ambiguity set and the fourth ambiguity set by modeling a predictive filter in accordance with the following inputs or states of the filter:
• motion data on the object, troposphere data, ionosphere data, a single difference reference ambiguity set associated with third carrier signals from different secondary satellites, and a single difference reference ambiguity set associated with the fourth carrier signals from different secondary satellites, and a difference reference ambiguity set associated with the third carrier signals or the fourth carrier signals, by compensating for inter-channel bias in the double difference ambiguity sets by subtracting to subtract a pre-programmed or initial inter-channel bias data from a double difference code pre-fit residual;
• and
• determining a position of the object based on the measured first carrier phase, the measured second carrier phase, the estimated first integer ambiguity set, the estimated second integer ambiguity set, and at least one of the measured third carrier phase and the measured fourth carrier phase, and at least one of the compensated third ambiguity set and the compensated fourth ambiguity set.

A satellite navigation receiver for receiving Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) satellite signals wherein the improvement comprises a receiver data processing system comprising:

• a plurality of phase measurement devices configured to measure carrier phases of the received GPS and GLONASS satellite signals;
• a data processor configured to calculate double difference ambiguity sets associated with the GLONASS satellite signals;
• a bias estimator configured to estimate a compensation factor for inter-channel bias in the double difference ambiguity sets for a bias compensator by subtracting a pre-programmed or initial inter-channel bias data from a double difference code pre-fit residual;
• and
• a position estimator configured to determine a position of the receiver based on the measured carrier phases and compensated ambiguity sets compensated by the compensation factor for the GLONASS satellite signals.