Abstract: Aspects of the disclosure provide an apparatus that includes a receiving circuit and a processing circuit. The receiving circuit is configured to receive a satellite signal transmitted from a satellite. The satellite signal carries navigation bits that are transmitted with a navigation bit length. The processing circuit is configured to construct aiding navigation bits based on aiding ephemeris and almanac information that are provided by an aiding source other than the satellite signal. Further, the processing circuit is configured to strip the navigation bits from the satellite signal based on the aiding navigation bits to generate a post-stripping signal, and perform an integration on the post-stripping signal.

Abstract: Aspects of the disclosure provide a method of determining frame timing of one or more signals from one or more respective transmitters. The method determining first observation windows that correspond to first candidate segments of the one or more signals; calculating a first set of accumulated signal patterns, each accumulated signal pattern of the first set of accumulated signal patterns being calculated based on signal patterns in a respective subset of the first candidate segments of the one or more signals; determining whether a first set of accumulated synchronization words derived from the first set of accumulated signal patterns is consistent with a first set of corresponding benchmark synchronization words; and determining the frame timing of the one or more signals based on timing of the first observation windows when the first set of accumulated synchronization words is consistent with the first set of corresponding benchmark synchronization words.

Abstract: Aspects of the disclosure include a method for sharing satellite navigation messages. The method includes receiving a download report from a receiver. The download report indicates what portions of a satellite navigation message are currently stored by the receiver. The method also includes determining whether to update a satellite navigation message database associated with a server based on the portions of the satellite navigation message stored by the receiver. In response to determining that the satellite navigation message database should be updated, the method further includes requesting the receiver to transmit a subset of the satellite navigation message currently stored by the receiver to the server; receiving the subset of the satellite navigation message; and updating the satellite navigation message database associated with the server based on the received subset of the satellite navigation message.

Abstract: Aspects of the disclosure include a method of prioritizing generation of predicted ephemeris data. The method includes receiving, by a device through a data network, first ephemeris seed data of a subset of a plurality of satellites, identifying a first satellite and a second satellite of the plurality of satellites, the first satellite being potentially detectable by the device at an estimated position at a given time, and the second satellite being potentially undetectable by the device at the estimated position at the given time, and prioritizing generation of first predicted ephemeris data that represent a first orbit of the first satellite before generation of second predicted ephemeris data that represent a second orbit of the second satellite. The generation of the first predicted ephemeris is based on the first ephemeris seed data.

Abstract: A method of determining a navigational position from satellite navigation signals includes receiving at a satellite navigation receiver a plurality of satellite navigation signals, where each respective satellite navigation signal was transmitted by a respective satellite each of which belongs to one of a plurality of satellite navigation system. Each respective satellite navigation signal transmitted by the respective satellite includes time data based on a time base of a respective satellite navigation system to which the respective satellite belongs. The time data in at least one respective satellite signal is converted from the time base of the respective satellite navigation system to which the respective satellite belongs to make each satellite navigation signal usable with each other satellite navigation signal to derive the position. In one implementation, the conversion involves a known relationship between time bases, as well as a measured hardware correction, and results in a common time base.

Abstract: Aspects of the disclosure include a method for sharing satellite navigation messages. The method includes receiving a download report from a receiver. The download report indicates what portions of a satellite navigation message are currently stored by the receiver. The method also includes determining whether to update a satellite navigation message database associated with a server based on the portions of the satellite navigation message stored by the receiver. In response to determining that the satellite navigation message database should be updated, the method further includes requesting the receiver to transmit a subset of the satellite navigation message currently stored by the receiver to the server; receiving the subset of the satellite navigation message; and updating the satellite navigation message database associated with the server based on the received subset of the satellite navigation message.