Abstract: Accurate long term satellite models for satellites include satellites of different navigation systems. Such a model is derived for a non-GPS satellite that broadcasts native orbital model data specified as valid within a first time period. Initial position and velocity data are determined from the native orbital model data, and orbit integration is performed to determine an orbital arc in an earth-centered-earth-fixed frame over a second time period longer than the first time period. Initial estimates of GPS or GPS-like orbit parameters are determined for the non-GPS satellite, and the orbital arc and the initial estimates of the GPS or GPS-like orbit parameters are input to an orbit parameter solver that determines GPS or GPS-like parameters that fit the orbital arc and is used to determine final orbital model parameters in GPS or GPS-like format for the non-GPS satellite.

Abstract: An improved extended ephemeris navigation receiver includes a fully autonomous satellite navigation receiver for receiving microwave transmissions from orbiting navigation system satellites, and able to demodulate navigation messages that include the ephemerides for those navigation system satellites. The improvements include a force model of the accelerations acting on a particular satellite vehicle, and are exclusive to the receiver. A single observation of the ephemeris for each SV is input and propagated days into the future by integrating each SV's orbital position with its corresponding force model. The fully autonomous satellite navigation receiver thereafter has available to it extended ephemeris predictions that can be used as substitutes when said navigation messages from the respective SV cannot otherwise be immediately obtained and demodulated.

Abstract: A tightly coupled GPS and dead-reckoning system collects wheel speed transducer data over a vehicle's network to compute vehicle range and direction. The dead-reckoning bridges over gaps in navigation solutions that would otherwise occur when GPS signal transmission is lost in tunnels, parking garages, and other common situations. Continual calibration of the wheel radii and compensation for speed effects are calculated from GPS position fixes, and such improves the performance and accuracy of dead-reckoning during long outages of GPS signal reception. When the GPS signals are restored, the dead-reckoning solutions provide a high quality starting place for the GPS receiver to search around.

Abstract: A satellite navigation system assistance server is configured to reply to client requests that include an indication of the client's location, and if an accurate location is included in the server request, the satellite navigation system assistance server computes which particular SBAS systems are observable to the requesting client, and in this case the satellite navigation system assistance server limits its replies to pertinent information for a more compact response message.

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A roving extended range high sensitivity satellite positioning system receiver provides position fixes in adverse signal conditions as low as minus 150 dbm and with as few as three satellites by measuring the bit phase of the navData message and the codephase, and finding a simultaneous solution. Previous position fixes that were obtained in the vicinity by earlier rovers are deposited in an indexed database for consultation. A cellular phone system can be used to simply communicate the current identity codes and their database entries.

Abstract: A mobile GPS-aiding system uses a GPS reference receiver to collect GPS navigation messages, a GPS-aiding data network server to distribute over the Internet all ephemeris and almanac data gleaned from the navigation messages, a number of commercial broadcast radio stations to publish such ephemeris and almanac data on particular sub-carriers, a number of vehicles equipped to receive the radio broadcasts and the sub-carriers and to retransmit them locally, e.g., via Bluetooth. Portable GPS receivers, operated near any of the vehicles, a receive Bluetooth transmissions with the ephemeris and almanac data with the identity of the radio broadcast station then being tuned. A breadcrumb database is used to index the locations of the radio broadcast stations. Each mobile GPS receiver contributes to such database after it computes a location fix. If the location of the radio broadcast station is already known to the database, then the location can be accessed and used before finding a position solution.

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A wireless handheld GPS-enabled device and supporting system comprises a wireless CPU that functions as a host processor, a GPS chipset to provide GPS measurements, and a GPS application hosted by the wireless CPU. Other applications are also hosted by the wireless CPU and are provided with position solutions from the GPS application. The GPS application calls for GPS aiding information from an Internet server via a TCP/IP socket provided by a GPRS link supported by the wireless CPU. Location area identifier (LAI) and “breadcrumb” information are provided to the GPS application so it can skip having to make a z-count determination during initialization.

Abstract: A GPS receiver depends on CMOS technology for both its GPS digital signal processing (DSP) and radio frequency (RF) stages. A resulting increase in RF input noise generated by the CMOS RF input is overcome by placing the antenna on-chip or on a lid of an application specific integrated circuit (ASIC) that includes the DSP and RF stages, and matching it for the best noise figure rather than the best impedance match. The on-chip antenna is matched to the natural high impedance of the CMOS RF input without requiring matching networks that can attenuate already weak signals. Using CMOS technology for both the GPS DSP and RF stages eliminates the need for level shifts between what would otherwise be a 3-volt RF section and a 1.2-volt DSP section.

Abstract: A navigation satellite receiver accepts satellite-position table messages comprising truncated GPS ephemeris parameters. In particular, at least one of the two harmonic corrections to inclination angle, Cic and Cis, are not communicated and not used in the solution of navigation receiver position. In a first method embodiment of the present invention, both the two harmonic corrections to inclination angle, Cic and Cis, are omitted from the computation. In a second method embodiment of the present invention, only one of the two harmonic corrections to inclination angle, Cic and Cis, are omitted from the computation, depending on Min(Cis sin(2?k), Cis cos(2?k)).

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power “off”. On power “restart”, a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.

Abstract: A combination mobile phone and navigation satellite receiver comprises a circuit for correcting GPS receiver reference frequency drift by using VCO burst information periodically received by a PDC handset. A corrected GPS receiver reference frequency drift then enables faster initialization and stable operation of the position solutions made available to users. A GPS numeric controlled oscillator (NCO) receives a PDC handset VCO sample.

Abstract: A cellphone system comprises a GPS reference station located with a telephone cell site. Such GPS reference station tracks the GPS satellites visible to its local area and estimates the Doppler for each such GPS satellite. The system also includes mobile GPS receivers and cellphones that move around and through the operational area of the cell site. It is assumed that the satellite Dopplers seen by the GPS reference station will have insubstantial differences with the true Dopplers observed by other GPS receivers operating within the cell site's service area. The Doppler estimates are thus routinely communicated over a wireless telephone channel to the mobile GPS receivers and cellphones that register locally. Such mobile GPS receivers then can confidently adopt the surrogate Doppler estimates as a center starting point for their initialization frequency searches. The time required for such mobile GPS receivers and cellphones to initialize and provide a first fix is thereby substantially reduced.

Abstract: A navigation-satellite receiver comprises high-sensitivity radio frequency front-end and navigation processor associated with a client CPU. The client CPU runs an operating system that serially communicates with the navigation processor. The client CPU is also able to obtain navigation data system transmissions from a network server and provides such when the direct satellite signals in the high-sensitivity environment are too weak to be demodulated directly. A low power, low frequency oscillator with a watch-type crystal and counter are used as a real time clock to keep time uncertainty under fifty milliseconds when the receiver is hibernating. If the time uncertainty and position uncertainty are below certain maximums when the receiver is re-awakened, then a minimum number of satellites will be needed and making a preliminary z-count to each can be avoided.

Abstract: A bootstrapping tandem navigation receiver system includes two independent navigation receivers. A first uses coherent detection and makes carrier-phase pseudorange measurements. A second uses non-coherent detection and a longer predetection interval and thus can acquire satellites in very weak signal environments. The second navigation receiver delivers a bootstrapping message to the first receiver that allows it to directly acquire the satellites without searching for them. The first navigation receiver then drives to find carrier phase lock and produces its more accurate measurements.

Abstract: A roving extended range high sensitivity satellite positioning system receiver provides position fixes in adverse signal conditions as low as minus 150 dbm and with as few as three satellites by measuring the bit phase of the navData message and the codephase, and finding a simultaneous solution. Previous position fixes that were obtained in the vicinity by earlier rovers are deposited in an indexed database for consultation. A cellular phone system can be used to communicate the vicinity ID's and their database entries.