Abstract: A system and method for estimating the location of a wireless device. A set of satellites may be determined as a function of an approximate area in which the wireless device is located. Assistance data is transmitted to the device including information from the set of satellites, and a location of the device may be estimated from the information where the assistance data prevents the wireless device from searching for signals from one or more satellites in the set of satellites. The one or more satellites may be an operable satellite but signals therefrom cannot be measured or acquired by the wireless device.

Abstract: A method and apparatus for determining the location of a device from signals provided by a plurality of satellites. A device receives a first plurality of signals comprising one signal from each of a first plurality of satellites and determines a first location of the device as a function of the first plurality of signals. The device then determines a second location thereof as a function of a second plurality of signals if the first location is not within a predetermined threshold. The second plurality of signals is a first subset of the first plurality of signals.

Abstract: A method of tracking a position of a transmitting apparatus in a sensor network is provided. The transmitting apparatus may receive Global Positioning System (GPS) information from each of satellites, may extract satellite time information and satellite identification information from the GPS information, may generate a transmission frame together with receiving time information and apparatus identification information, and may transmit the transmission frame to a receiving apparatus.

Abstract: A navigation system for detecting error on Doppler frequencies of a plurality of satellite signals measured by the navigation system is disclosed herein. The navigation system includes an offset calculator for calculating offsets of the Doppler frequencies of the satellite signals during a predetermined time period and calculating an average value of the offsets. The navigation system further includes an error detecting unit coupled to the offset calculator. The error detecting unit compares the offsets of the Doppler frequencies of the satellite signals with the average value of the offsets and determines whether the satellite signals are unavailable according to corresponding comparison results.

Abstract: A method of managing additional filters in a navigation system fitted to a vehicle, the system acting, during a journey of the vehicle, to deliver at least one position of the vehicle by using a main filter for merging data coming from a constellation of visible satellites present above a vehicle horizon, each additional filter excluding data coming from one of the satellites in order to obtain a corrected position in the event of failure of the excluded satellite. The steps including from a position of the vehicle, determining a theoretical constellation of satellites present above the horizon; and for each satellite present in the theoretical constellation, creating and maintaining an additional filter excluding that satellite.

Abstract: A positioning device 20 receives a satellite signal from a satellite positioning system (SPS) satellite and locates a present position, the positioning device 20 including an azimuth calculation section which calculates an azimuth of the SPS satellite corresponding to the received satellite signal, and a reception environment determination section which determines a reception environment including a multipath environment based on the azimuths of the SPS satellites calculated by the azimuth calculation section.

Abstract: 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.

Abstract: A global navigation satellite system (GNSS) receiver comprising one or more regular channel circuits and one or more sniff channel circuits may be operable, utilizing the sniff channel circuits, to monitor power levels of currently visible GNSS satellites which are not being utilized by the regular channel circuits. An alternative GNSS satellite from the currently monitored GNSS satellites may be selected by the GNSS receiver based on the monitored power levels. GNSS signals received from the selected alternative GNSS satellite may be processed by a regular channel circuit. The GNSS receiver may be operable to detect, for example, signal-to-noise ratios (SNRs) or carrier-to-noise density ratios (C/N0s) of the currently visible GNSS satellites utilizing the sniff channel circuits. The sniff channel circuits may not be utilized to generate GNSS measurements so that functionality of each of the sniff channel circuits may be reduced.

Abstract: A system and method for determining one or more satellites in view of a wireless device. A request for satellite assistance data may be received from a requesting entity and a reference location determined as a function of the request. A set of satellites may be determined as a function of the reference location. Subsequent cached information may be determined for each satellite in the set of satellites if cached information already existing for each satellite in the set of satellites has been cached for greater than a predetermined time period. This subsequent cached information may then replace the previously existing cached information for the reference location. One or more satellites in view of the wireless device may then be determined as a function of either the subsequent cached information or previously existing cached information, and assistance data may be provided to the requesting entity to determine an estimated location of the wireless device.

Abstract: A low power, lightweight, collapsible and rugged antenna positioner for use in communicating with geostationary, geosynchronous and low earth orbit satellite. By collapsing, invention may be easily carried or shipped in a compact container. May be used in remote locations with simple or automated setup and orientation. Azimuth is adjusted by rotating an antenna in relation to a positioner base and elevation is adjusted by rotating an elevation motor coupled with the antenna. Manual orientation of antenna for linear polarized satellites yields lower weight and power usage. Updates ephemeris or TLE data via satellite. Algorithms used for search including Clarke Belt fallback, transponder/beacon searching switch, azimuth priority searching and tracking including uneven re-peak scheduling yield lower power usage. Orientation aid via user interface allows for smaller azimuth motor, simplifies wiring and lowers weight. Tilt compensation, bump detection and failure contingency provide robustness.

Abstract: A method and apparatus for determining the location of a device from signals provided by a plurality of satellites. A device receives a first plurality of signals comprising one signal from each of a first plurality of satellites and determines a first location of the device as a function of the first plurality of signals. The device then determines a second location thereof as a function of a second plurality of signals if the first location is not within a predetermined threshold. The second plurality of signals is a first subset of the first plurality of signals.

Abstract: Systems and methods are provided to allow for the use of existing satellite identification parameters generically, so as to allow for Global Navigation Satellite System (GLONASS) identification. In addition, an optional or conditional parameter is linked to the satellite identification parameter for a frequency identification, where frequency identification is indicative of a Frequency Division Multiple Access (FDMA) frequency value. Such a frequency identification parameter is optional as it is needed only for current GLONASS and/or near-future GLONASS (e.g., GLONASS-M) satellites. Hence, utilization of the frequency identification parameter maybe unnecessary and therefore, not included/not linked when considering next generation GLONASS satellites, e.g., GLONASS-K satellites. Additionally, signals supported by particular global positioning system (GPS) satellites can be indicated with the use of generic satellite identification.

Abstract: A positioning method that performs current position calculations and outputs a positioning result position includes searching for satellite signals transmitted from positioning satellites to acquire satellites, combining satellites among the acquired satellites to extract satellite sets used for positioning, performing first positioning calculations on each calculation-target satellite set among the extracted satellite sets using the satellite signals transmitted from the acquired satellites included in the calculation-target satellite set, performing second positioning calculations on each calculation-target satellite set among the extracted satellite sets using the satellite signals transmitted from the acquired satellites that are included in the calculation-target satellite set, but do not include a low-elevation-angle satellite, and determining whether or not a positioning result obtained using the calculation-target satellite set is appropriate based on the difference between a position calculated by th

Abstract: A method for obtaining correct phase inversion points in a signal of global positioning system (GPS) includes the following steps. A satellite signal from one of a plurality of satellites is received continuously. A plurality of phase inversion points in the received satellite signal is interpreted. Each time difference between each two adjacent phase inversion points among the plurality of phase inversion points is calculated. It is determined whether each of the time differences is an integral multiple of 20 milliseconds. A data is retrieved every 20 milliseconds from the satellite signal by using a first phase inversion point in the plurality of phase inversion points as a starting point when each of the time differences is an integral multiple of 20 milliseconds. By finding out a plurality of correct phase inversion points in the satellite signal, the positioning speed is increased, and thus a positioning time required is reduced.

Abstract: A positioning device 20 receives a satellite signal from a satellite positioning system (SPS) satellite and locates a present position, the positioning device 20 including an azimuth calculation section which calculates an azimuth of the SPS satellite corresponding to the received satellite signal, and a reception environment determination section which determines a reception environment including a multipath environment based on the azimuths of the SPS satellites calculated by the azimuth calculation section.

Abstract: A communication device is provided which includes a positioning information receiving portion that receives positioning information, by wireless signal, from another communication device, the positioning information including first satellite orbit information that indicates respective orbits of a specific number of satellites and position information that indicates a position of the other communication device, an initialization processing portion that performs initialization processing that specifies, based on the positioning information received by the positioning information receiving portion, from among the specific number of satellites, a plurality of satellites transmitting satellite signals that can be received by the communication device.

Abstract: A satellite time dynamic search method and a receiver implementing such a method are disclosed. In the present invention, a predetermined period of time is sampled into multiple time samples. The time samples are sieved according to a search result of a satellite selected from candidate satellites each time. By repeatedly doing so, the finally remaining time sample will approach a true satellite system time, and accordingly the candidate satellites converge to the most possible ones as to facilitate satellite search.

Abstract: A satellite search method and a receiver implementing such a method are disclosed. In the present invention, a predetermined range is sampled into multiple possible positions or space-time points, each of which is defined by a specific position and a time sample. The possible positions or points are sieved according to a search result of a satellite selected from candidate satellites each time. By repeatedly doing so, the finally remaining position will approach a user's position, and accordingly the candidate satellites converge to the most possible ones as to facilitate satellite search.

Abstract: The vector coordinates of each acquired satellite are calculated, the vector coordinates being given by the coordinates of an end point of a vector of which the direction coincides with the direction (azimuth) of the corresponding acquired satellite based on the present position and the magnitude corresponds to a signal strength. An overall BOP that indicates the deflection of the acquired satellite signals is calculated by adding up the vector coordinates of each acquired satellite signal. The position of the overall BOP indicates the direction of deflection (deflection azimuth) of the acquired satellite signals, and the distance from an origin O indicates the degree of deflection (deflection strength) of the acquired satellite signals.

Abstract: A terminal apparatus includes a control unit and a positioning device. The control unit determines a first satellite-to-be-acquired from among a plurality of SPS satellites, and generates an initial search frequency for the first satellite-to-be-acquired. The positioning device has a plurality of search units, and is configured to acquire the first satellite-to-be-acquired using the plurality of search units. The control unit determines first difference information, which is a difference between the initial search frequency and the frequency at which the first satellite-to-be-acquired is acquired. The control unit generates corrected search frequencies for other SPS satellites, using the first difference information. The positioning device acquires other necessary SPS satellites using the corresponding corrected search frequencies. The terminal apparatus can acquire SPS satellites accurately even when there has been a frequency shift in the terminal apparatus since the last positioning.

Abstract: A time adjustment device has a reception unit that receives a satellite signal transmitted from a positioning information satellite, a time information generating unit that generates internal time information, and a time information adjustment unit that adjusts the internal time information. The satellite signal contains satellite time information that is kept by the positioning information satellite. The reception unit includes a signal level acquisition unit that searches for positioning information satellites and acquires the signal level of the satellite signal transmitted from each positioning information satellite, a reception satellite selection unit that selects a positioning information satellite based on the acquired signal level, and a satellite time information acquisition unit that receives the satellite signal transmitted from the positioning information satellite selected by the reception satellite selection unit, and acquires the satellite time information contained in the satellite signal.

Abstract: A system and method for determining one or more satellites in view of a wireless device. A request for satellite assistance data may be received from a requesting entity and a reference location determined as a function of the request. A set of satellites may be determined as a function of the reference location. Subsequent cached information may be determined for each satellite in the set of satellites if cached information already existing for each satellite in the set of satellites has been cached for greater than a predetermined time period. This subsequent cached information may then replace the previously existing cached information for the reference location. One or more satellites in view of the wireless device may then be determined as a function of either the subsequent cached information or previously existing cached information, and assistance data may be provided to the requesting entity to determine an estimated location of the wireless device.

Abstract: A method for searching satellites in a cold start state. The method of the present invention, a first satellite, which is predetermined or randomly selected, is searched. Then, a second satellite to be searched is selected according to the searching result (hit or missed) for the first satellite and respective interrelationships between the first satellite and the other satellites. In practice, an initial weight factor table is provided. Depending on the searching result, the initial weight factor table is updated according to the interrelationships between the satellites during searching. By using the method of the present invention, the time-to-first-fix (TTFF) can be reduced to a shorter period of time so as to provide a rapid cold start satellite positioning.

Abstract: Locating satellites (e.g., GPS) are culled into a sub-plurality based largely on dwell time within an inverted cone above a relevant site in communication with a wireless device. A first inverted cone having a first base angle is defined above a first site, a second inverted cone having a second base angle is defined above a second site. If the second site is farther from an equator of Earth than the first site, then the second inverted cone is made to have a base angle larger than a base angle of the first inverted cone. If the first site is farther from the equator of Earth than the second site, then the first inverted cone is made to have a base angle larger than a base angle of the second inverted cone. The span of the inverted cone over the site closest to the equator may be limited.