Positioning determinations of receivers

摘要

The disclosed method and system is used to determine the position of a user device. The user device can receive data signals and/or carrier signals from orbiting space vehicles. These data signals can be used for positioning calculation and/or track maintenance of the user device. The disclosed method and system can account for time and frequency biases of the user device. For the track maintenance, a Kalman filter state estimator can be extended to include a velocity of the user device.