| 摘要 |
Methods and systems are provided for accessing GPS signals in faded environments. Means are provided for predicting the nonlinear phase induced by the receiver's own clock, when there is at least one GPS satellite link strong enough to calculate a phase profile. In an embodiment, GPS signals are accessed in faded environments by increasing the sensitivity of a GPS receiver by increasing the processing gain of received GPS signals through increased integration time. Matching a near-baseband signal requires removing a nonlinear part of the phase which may arise from several sources, including: the phase drift of the GPS satellite's atomic clock, the phase drift due to the motion of the GPS receiver, the phase drift due to the motion of the GPS satellite, and the phase drift due to the GPS receiver's clock.
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