Patent ID: 9645245
Date: 2017-05-09
CPC Classifications: G01S

Claim:
1. A method of determining a position of an antenna of a global navigation satellite system (GNSS) receiver, the method comprising: tracking satellites of at least two GNSS systems to obtain first observation data from one or more satellites of a first GNSS system of the at least two GNSS systems and to obtain second observation data from one or more satellites of a second GNSS system of the at least two GNSS systems, the first observation data and the second observation data obtained over a number of epochs, the first observation data including pseudo range, carrier phase, and timing data based on a clock of the first GNSS system, and the second observation data including pseudo range, carrier phase, and timing data based on a clock of the second GNSS system; estimating a first clock difference between the clock of the first GNSS system and a clock of the GNSS receiver; estimating a second clock difference between the clock of the second GNSS system and the clock of the GNSS receiver independently from estimating the first clock difference; determining a constraint regarding a difference between the first clock difference and the second clock difference; and when at least four satellites are tracked, computing a standalone antenna position of the GNSS receiver using the first observation data and the second observation data of the tracked satellites, the first clock difference and the second clock difference, and the constraint.