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 security system comprises a secured asset associated with a high-sensitivity GPS receiver that can receive network aiding information. Indoors, the pseudo-ranges from orbiting GPS satellites can be computed by using digital correlators to pull directly received satellite signal transmissions from the noise floor, but the NAV-data transmissions cannot be demodulated well enough due to the attenuation caused by the building structure. So a wireless network is relied upon to provide aiding information that supplies the almanac and ephemeredes. The fact that the NAV-data transmissions cannot be demodulated well enough is taken as indicia that the system is being operated indoors, and such can be used in a geo-fence control to decide if indoor or outdoor use is not permitted. The secured asset can be temporarily or permanently disabled according to such geo-fence controls.

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 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 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 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 method for correcting frequency errors in the local reference frequency crystal oscillator of a GPS receiver begins with a step in which the ordinary temperature response of a crystal is characterized. A hardware circuit is incorporated with that crystal to mirror that same characteristic. A temperature sensor is used to control a compensation applied. The combination outputs a fairly flat temperature response, e.g., near zero delta-frequency change over the operating temperature range. But this flat response has an unknown offset from the true frequency. A next step finds a precision timing reference, such as when the receiver locks onto and tracks GPS satellites. The receiver then knows time precisely and a navigation software can compute the offset accurately. A value is stored for that offset in memory. Such value is thereafter recalled at each cold start and is used by software to remove the expected frequency offset.

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 navigation receiver comprises a digital sampler that precedes digital signal processing which can operate at a high rate and a low rate. If the high rate is selected for noise reduction by non-coherent averaging, the samples are averaged over time and transformed to the low rate. The digital signal processor is fed only low-rate samples in either case.

Abstract: A navigation receiver comprises a digital sampler that precedes digital signal processing which can operate at a high rate and a low rate. If the high rate is selected for noise reduction by non-coherent averaging, the samples are averaged over time and transformed to the low rate. The digital signal processor is fed only low-rate samples in either case.

Abstract: A navigation system comprises a cell-phone, a base cellular telephone site, and a webserver. Each is paired with a GPS receiver. The GPS receiver associated with the cell-phone is aided with information received from the cell-site and webserver that help reduce satellite search uncertainty. Time difference and/or frequency difference measurements are taken with data collected from what the cell-phone and its GPS receiver assume to be accurate time and frequency. Correction information is used in post-processing of the velocity solutions computed by the cell-phone to arrive at more precise determinations for the system.

Abstract: A navigation system comprises a cell-phone, a base cellular telephone site, and a webserver. Each is paired with a GPS receiver. The GPS receiver associated with the cell-phone is aided with information received from the cell-site and webserver that help reduce satellite search uncertainty. Time difference and/or frequency difference measurements are taken with data collected from what the cell-phone and its GPS receiver assume to be accurate time and frequency. Correction information is used in post-processing of the velocity solutions computed by the cell-phone to arrive at more precise determinations for the system.

Abstract: A satellite-navigation system comprises an observer platform for collecting signal observations from orbiting navigation satellites. A server platform provides a simplified navigation-satellite constellation almanac, ephemeris, differential correction, and client services. A navigation platform passes information between the observer and server platforms and provides for autonomous position solution computations for a limited time after a periodic call for an aiding data from the server platform. A measurement platform included in the server platform makes static observations of a navigation-satellite constellation and that builds a database of measurement errors and satellite data messages. A health and quality monitor included in the server platform checks the static observations and preventing an inclusion of incorrect information in the database of measurement errors and satellite data messages.

Abstract: A system and method which separates time critical interrupt driven processing of Global Positioning System (GPS) signals from non-time critical processing. A measurement platform performs all satellite tracking functions which are driven by interrupts. Intermediate measurements data generated therefrom, for example code phase, carrier phase and Doppler, are communicated to a user platform which computes receiver position and time. As a result, the user platform can easily be configured to perform user-specific processes without incurring conflicts with the interrupt driven processes occurring on the measurement platform.

Abstract: A system and method which enables a user platform to perform low level control of a channel unit which performs acquisition and tracking of Global Positioning System (GPS) signals processing the measurement platform which includes the channel and that performs all satellite tracking functions which are driven by interrupts. Intermediate measurements data generated therefrom, for example code phase, carrier phase and Doppler, are communicated to a user platform which computes receiver position and time. As a result, the user platform can easily be configured to perform user-specific processes without incurring conflicts with the interrupt driven processes occurring on the measurement platform. Furthermore, the user platform is configured to issue commands to the channel unit to control the operation of the measurement platform. Thus, the performance of the measurement platform can be tailored specifically to the end user application.

Abstract: An improved GPS navigation receiver for converting range and range-rate information from microwave radio transmissions from orbiting satellites and for determining a position of the receiver from a processing of the information and an output connected to provide the determined position on a display. The improvement comprises a database of maps stored in a portable document format (PDF) file independent of any hardware, software and operating system used to create it. The PDF file provides for a description of documents including any combination of text, graphics and images in a device-independent and resolution-independent format. The database is connected to output selected ones of the maps on the display with hypertext access on points-of-interest.

Abstract: A geographical position/image capturing system stores object images and position coordinates as digital data. The system incorporates a geo-addressed map data base and geo-positioning device for relating the position of the system at the time the image is captured to the captured digital image data and the geo-addressed map. A point-of-interest feature data base is linked to the image data and the position data, by hyper-media links. Digital multi-media entities such as graphics, video clips, audio streams and the like can be digitally stored and retrieved based on hyper-media links coupling the entities to the object images, the map position and feature data base. A playback unit incorporating an image viewer communicates with the stored digital digital image data, the multi-media entities, the map data base, and the feature data base and allows modified images of selected portions of the images and other data to be viewed by a user.