Abstract: Method and apparatus for processing satellite signals in an SPS receiver is described. In one example, the satellite signals are correlated against pseudorandom reference codes to produce correlation results. A determination is made whether the SPS receiver is in a motion condition or a stationary condition. The correlation results are coherently integrated in accordance with a coherent integration period. The coherent integration period is a value that depends upon the motion condition of the SPS receiver.

Abstract: A method and apparatus for background decoding of a broadcast satellite-navigation message to maintain integrity of long-term-orbit information used in a Global-Navigation-Satellite System or other positioning system is described. The method may include processing the long-term-orbit information associated with at least one satellite to obtain a first position of a receiver; obtaining at least one portion of broadcast ephemeris transmitted from the at least one satellite; and processing, as a substitute for at least one portion of the long-term-orbit information, the at least one portion of broadcast ephemeris to obtain a second position of the receiver.

Abstract: A method and apparatus for determining long term orbit (LTO) models using variable time-horizons to improve the orbit and clock model accuracy. The method and apparatus use either historic ephemeris or historic measurements for at least one satellite to produce an orbit parameter prediction model (an LTO model). The parameter predicted by the model is compared to an orbit parameter of a current broadcast ephemeris. The result of the comparison (an indicia of accuracy for the model) is used to establish a time-horizon for the orbit parameter prediction model for that particular satellite. Such a time-horizon may be established in this manner for each satellite within a satellite constellation.

Abstract: A method and apparatus for processing long term orbit data that is valid for an extended period of time into the future (i.e., long term orbit data). The long term orbit data is processed by reducing redundant information from the data to form compressed long term orbit data.

Abstract: Method and apparatus for receiving an estimate of time in a satellite signal receiver receives an estimate of time from a server and compensates for error of a clock in the satellite signal receiver using the estimate of time. The output of the compensated clock is used when computing a position of the satellite signal receiver. The estimate of time is received using a network time protocol (NTP), a simple network time protocol (SNTP), or by one-way broadcast from the server.

Abstract: Method and apparatus for processing satellite signals in an SPS receiver is described. In one example, the satellite signals are correlated against pseudorandom reference codes to produce correlation results. A determination is made whether the SPS receiver is in a motion condition or a stationary condition. The correlation results are coherently integrated in accordance with a coherent integration period. The coherent integration period is a value that depends upon the motion condition of the SPS receiver.

Abstract: Method and apparatus for validating an initial position in a satellite positioning system using range-rate measurements is described. In one example, range-rate measurements are obtained at the remote receiver with respect to a plurality of satellites. Expected range-rates are computed with respect to the plurality of satellites using the initial position. Single differences are computed using the range-rate measurements. Expected single differences are computed using the expected range-rates. Single difference residuals are computed between the single differences and the expected single differences. The single difference residuals are compared to a threshold. The initial position may be deemed valid if the absolute value of each of the single difference residuals is less than or equal to the threshold. A valid initial position may be used to fix the pseudorange integers.

Abstract: A method and apparatus for locating position of a satellite signal receiver is described. In one example, a Doppler offset for each of a plurality of satellite signals relative to the satellite signal receiver is determined at a first time. A position of the satellite signal receiver is then computed using the Doppler offset for each of the plurality of satellite signals. In another example, at least one pseudorange between the satellite signal receiver and a respective at least one satellite is determined. At least one Doppler offset for a respective at least one satellite signal relative to the satellite signal receiver is also determined. A position of the satellite signal receiver is computed using the at least one pseudorange and the at least one Doppler offset.

Abstract: Method and apparatus for decoding a bitstream of navigation data broadcast by a satellite positioning system satellite is described. In one example, a portion of a subframe in the navigation data for each of a plurality of occurrences of the subframe in the bitstream is obtained at a satellite signal receiver to produce a respective plurality of subframe portions. The subframe portions are then combined to recover the subframe. The subframe portions may be processed to maintain a constant polarity by comparing a common sequence of data bits among at least two of the subframe portions to identify a mismatch in polarity.

Abstract: Method and apparatus for location-based triggering in a mobile receiver is described. In one example, a triggering region is designated. Expected pseudorange data is generated within the mobile receiver and pseudoranges to a plurality of satellites are measured. A delta position is computed with respect to a virtual center of the triggering region using satellite trajectory data, the measured pseudoranges, and the expected pseudoranges. The delta position is compared with the radius restriction value, the results of which may be used to trigger an event. In another example, expected pseudorange data is obtained at the mobile receiver. Pseudoranges from the mobile receiver to a plurality of satellites are measured. The measured pseudoranges and expected pseudoranges are compared using a metric to produce delta values. The delta values are compared with a radius restriction value, the results of which may be used to trigger an event.

Abstract: Method and apparatus for adjusting acquisition assistance data received by a mobile receiver from a server is described. In one example, pseudoranges are measured from the mobile receiver to a set of satellites. Line-of-sight data is obtained with respect to the mobile receiver and the set of satellites. The pseudoranges and the line-of-sight data are processed to compute updates for an initial position associated with the acquisition assistance data and a correlator clock bias associated with the pseudoranges. The acquisition assistance data is then adjusted using the updates and the line-of-sight data.

Abstract: Method and apparatus for processing position information in a mobile device is described. In one example, a request for a position to be computed within a predefined period of time is received. A plurality of positions is calculated within the predefined period of time. At least one of the plurality of positions is cached in a position cache. Accuracy data is derived with respect to at least one of the plurality of positions. A best position stored in the position cache is identified in response to the accuracy data. The best position may be sent to a server in communication with the mobile device.

Abstract: Method and apparatus for locating position of a remote receiver is described. In one example, long term satellite tracking data is obtained at a remote receiver. Satellite positioning system (SPS) satellites are detected. Pseudoranges are determined from the remote receiver to the detected SPS satellites. Position of the remote receiver is computed using the pseudoranges and the long term satellite tracking data. SPS satellites may be detected using at least one of acquisition assistance data computed using a previously computed position and a blind search. Use of long term satellite tracking data obviates the need for the remote receiver to decode ephemeris from the satellites. In addition, position of the remote receiver is computed without obtaining an initial position estimate from a server or network.

Abstract: Method and apparatus for locating position of a satellite signal receiver is described. In one example, pseudoranges are obtained that estimate the range of a satellite signal receiver to a plurality of satellites. An absolute time and a position are computed using the pseudoranges at a first time. The absolute time is then used to compute another position at a subsequent time. In another example, a plurality of states associated with a satellite signal receiver are estimated, where the plurality of states includes a time tag error state. A dynamic model is then formed relating the plurality of states, the dynamic model operative to compute position of the satellite signal receiver.

Abstract: A method and apparatus for locating position of a GPS device is described. In one example, a wireless carrier is provided in communication with the GPS device. The wireless carrier is configured to provide an approximate position of the GPS device. A server is provided for generating an initialization packet having a satellite orbit model configured for the approximate position. The GPS device is configured to compute pseudo-noise code phase information using the satellite orbit model of the initialization packet. The server is configured to compute position of the GPS device using the pseudo-noise code phase information. A web portal is provided to facilitate communication among the GPS device, the wireless carrier, and the server. In one example, a position request is generated at the web portal. In another example, the position request is generated at the GPS device.

Abstract: A method and apparatus for monitoring the integrity of satellite tracking data used by a remote receiver is described. In one example, a first set of satellite tracking data is received at a server. Integrity data for a second set of satellite tracking data is generated using the first set of satellite tracking data. The integrity data is then transmitted to at least one remote receiver having the second set of satellite tracking data.