| 摘要 |
A method of collecting information for supplementing a trusted estimate of position. The method comprises: receiving first information sufficient to derive a trusted estimate of a first position; receiving an indication that a supplementary estimate of a second position in the vicinity of the first position may be required; in response to the indication, sensing information comprising the identity of at least one terrestrial wireless source observable in the vicinity of the first position; and storing the sensed information in association with the first position. The method enables the trusted estimate of the first position to subsequently be used to estimate any said second position from which the at least one wireless source is observable. |
