摘要:
A method and apparatus for distribution and delivery of global positioning system (GPS) satellite telemetry data using a communication link between a central site and a mobile GPS receiver. The central site is coupled to a network of reference satellite receivers that send telemetry data from all satellites to the central site. The mobile GPS receiver uses the delivered telemetry data to aid its acquisition of the GPS satellite signal. The availability of the satellite telemetry data enhances the mobile receiver's signal reception sensitivity.
摘要:
Embodiments of the present disclosure use shared oscillator for cellular communications and location detection in a communication device. The communications device estimates a frequency offset of one of its subsystems. The communications device determines a frequency offset that results from drifting of this shared oscillator, typically caused by aging and/or changes in temperature, voltage, humidity, pressure, and/or vibration to provide some examples, from the frequency offset this subsystem. The communications device provides various compensation parameters to its various subsystems to compensate for the frequency offset that results from drifting of the oscillator.
摘要:
Aspects of a method and system for keeping a device for satellite navigation in a state that enables rapid signal acquisition are provided. The device may acquire broadcast ephemeris from one or more satellite signals during a data refresh operation. The satellite signals may comprise a GPS signal, a GLONASS signal, a GALILEO signal, or a combination thereof. The device may compute extended or future ephemeris from the acquired broadcast ephemeris during the data refresh operation. In a positioning operation that is subsequent to the data refresh operation, the device may determine satellite navigation information from the computed extended ephemeris. In some instances, a time associated with a schedule of the data refresh operation may be adjusted based on the computed extended ephemeris. The extended ephemeris may be computed by integrating current and/or historic broadcast ephemeris into an orbit model.
摘要:
A device is disclosed that is capable of determining its location using high-power with high accuracy, and using low-power with lower accuracy. By coordinating usage between the high power method and the low power, overall power consumption of the device can be significantly reduced without a significant reduction in accuracy. Such high accuracy may be achieved through the use of a GNSS unit, such a GPS receiver. In addition, the low-power alternative may be achieved using an accelerometer, together with software, hardware or firmware for extrapolating a speed based on the force measurements by the accelerometer. In this manner, the GPS receiver can be operated for only a fraction of overall use, primarily to provide adjustment data necessary to calibrate usage of the accelerometer.
摘要:
Aspects of a method and system for extending the usability period of long term orbit (LTO) are provided. A GPS enabled handset may receive LTO data from an AGPS server via a wireless communication network such as 3GPP or WiMAX. The GPS enabled handset may be enabled to receive broadcast GPS signals. The GPS enabled handset may extract navigation information from the received broadcast GPS signals to be used to adjust the received LTO data. The usability period of the received LTO data may be extended, accordingly. A clock model and a satellite health model associated with the extracted navigation information may be used to update or replace the clock model and/or the satellite health model of the received LTO data, respectively. A navigation solution for the GPS enabled handset may be determined more accurately based on the adjusted LTO data.
摘要:
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.
摘要:
Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A first difference between a first time reference frame of the first satellite navigation system and a time reference and a second difference between a second time reference frame of the second satellite navigation system and the time reference are obtained. The at least one first pseudorange and the at least one second pseudorange are combined using the first and second differences in time references.
摘要:
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.
摘要:
A method and apparatus for determining time-of-day in a mobile receiver is described. In one example, expected pseudoranges to a plurality of satellites are obtained. The expected pseudoranges are based on an initial position of the mobile receiver and an initial time-of-day. Expected line-of-sight data to said plurality of satellites is also obtained. Pseudoranges from said mobile receiver to said plurality of satellites are measured. Update data for the initial time-of-day is computed using a mathematical model relating the pseudoranges, the expected pseudoranges, and the expected line-of-sight data. The expected pseudoranges and the expected line-of-sight data may be obtained from acquisition assistance data transmitted to the mobile receiver by a server. Alternatively, the expected pseudoranges may be obtained from acquisition assistance data, and the expected line-of-sight data may be computed by the mobile receiver using stored satellite trajectory data, such as almanac data.
摘要:
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.