| 摘要 |
A system for maintaining time in a satellite positioning system (SPS) receiver that relies on almanac data to maintain a reasonably accurate time. The approximate time based on almanac data is sufficiently accurate to bound the unknown parameters when a request for position is received. The receiver may automatically update the internal time and/or position. When a time update is required, the approximate time based on almanac data is sufficiently accurate that the receiver need only acquire the code phase from the satellites and can internally determine the code period into the bit and the bit into the week based on the almanac data.
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