In INS/GPS tightly-coupled integration, the carrier-phase derived delta pseudorange measurements are often used for velocity determination. However, it is a type of integrated measurements with errors strongly related to the pseudorange errors at the start and end of the integration interval. Conventional methods circumvent these errors with approximations, which may lead to large velocity estimation errors in high dynamic applications. In order to tackle this problem, two methods are proposed and compared in this paper. Sequential processing is used in both methods for measurement updates. Simulations are performed based on a field collected UAV trajectory. Numerical results show that the correct handling of the errors involved in the delta pseudorange measurements is critical for high dynamic applications, and that sequential processing can be used to update different types of measurements without degrading the system estimation accuracy if certain conditions are met.
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