1551 results about "Gps satellites" patented technology

The navigation system method described herein could guide people around urban environments, detect guide and navigate them to destinations, add-on to the portable phone. We have focused on the task of detecting and navigating even in situations in which Global Positioning Systems (GPS) cannot provide this information, such as when the person is indoors or in crowded urban areas where there is no line of site to the GPS satellites. The information will be received directly from RF sensors and will display on the existing cellular phone as Bluetooth application

A system and method for determining the attitude of a platform is provided. The method includes: (a) Searching and scanning for one or more GPS satellite(s) to determine initial platform position; wherein a single directionally steered antenna scans for the GPS / GNSS satellite; (b) pointing and scanning the antenna to GPS / GNSS satellite to determine a first angular measurement of a direction of a GPS / GNSS signal; (c) measuring carrier to noise ratio of the GPS / GNSS satellite; (d) dithering the single directionally steered antenna to obtain an angular measurement relative to an antenna pattern bore-sight reference; (e) repeating steps (b)-(d) to determine a second angular measurement of the direction of a second GPS signal; (f) determining the attitude error of the platform using the first and second angular measurements; (g) updating the platform position and attitude.

GPS satellites are culled into a minimum, preferred group having a longest dwell time within a cone of space, and communicated to mobile devices or subscribers within a particular region (e.g., serviced by a particular base station). The culling may initially be a list of GPS satellites visible to a particular base station at a particular time. As a preferred culling, only those GPS satellites currently within a cone of space above the relevant base station are selected for communication by a mobile device within the service area of the relevant base station. As an ultimate culling, a minimum set of GPS satellites may be selected based on, e.g., being not only within an arbitrary cone of space normal to the base station, but also projected to remain within that cone of space for the longest period of time, i.e., having the longest dwell time.

The parking detection system method described herein could guide people around urban environments, detect guide and navigate them to empty parking spaces, add-on to the car-based navigation systems that are popular today and or to the portable phone. We have focused on the task of detecting and navigating even in situations in which Global Positioning Systems (GPS) cannot provide this information, such as when the person is indoors or in crowded urban areas where there is no line of site to the GPS satellites. The parking information will be received directly from RF sensors and will display as a floating overlay on the existing cellular phone as Bluetooth application making the cellular phone a parking detector.

Methods and apparatuses for improved position determination of a device using multiple pseudo range measurements from transmitting sources at known locations, such as GPS satellites. A plurality of pseudo range measurements for each transmitting source are processed together to obtain a simplified maximum likelihood estimate for the pseudo range for that transmitting source at a common reference time. The processed pseudo range estimates for all transmitting sources are then combined using conventional position determination algorithms. This technique facilitates removal of raw measurement outliers prior to position determination, which results in improved (i.e., more accurate) position fixes of the device. In addition, improved measurement integrity monitoring of the pseudo range measurements is a feature of this invention.

The invention relates to an aided Global Positioning System (GPS) subsystem within a wireless device. The wireless device includes a wireless processing section capable of receiving signals from a wireless network and a GPS subsystem having a radio frequency (RF) front-end capable of receiving a GPS satellite signal. The wireless processing section of the wireless device receives an external clock and determines the offset between the clock in the wireless processing section and that of the external clock. The GPS subsystem then receives the offset information from the wireless processing section, information related to the nominal frequency of the wireless processing section clock and the wireless processing section clock. Using this information and the GPS clock in the GPS subsystem, the GPS subsystem determines an acquiring signal, which is related to a frequency offset between the GPS clock and the network clock. The GPS subsystem then acquires GPS satellite signals in an acquiring unit though the use of the acquiring signal.

A missile guidance system designed to operate on GPS signals in an anti-jamming environment. The inventive system includes first, second and third airborne vehicles (20). A GPS receiver (24) is mounted on each of the three vehicles (20) to receive signals transmitted from spaceborne satellites (14). Each vehicle (20) acts as a pseudo-satellite or "pseudolite'. The received GPS signals are processed by a processor (26) to provide a first intermediate signal indicating the position of the vehicle (20). This signal is retransmitted from each vehicle and received by a GPS receiver mounted on a missile. The received intermediate signal is processed on the missile to provide an output signal indicating the position thereof. The pseudolites would be airborne in the vicinity of a target area. Because the pseudolites are relatively close to the targets compared to a satellite in high altitude orbit and because the pseudolites would be able to transmit a kilowatt or more power, the signal strength may be improved significantly. To succeed as a jammer, a jammer, successful against GPS satellites, would need considerably more power to succeed against aircraft carried pseudolites. The pseudolite system delivers GPS signals into the target area 40-70 dB stronger than signals coming directly from GPS satellites. By timing the signals for 100% time coverage, enemy C / A code receivers will be jammed because they are limited to a J / S capability of 30 dB.

A positioning and navigation method and system thereof can substantially solve the problems encountered in global positioning system-only and inertial navigation system-only, such as loss of global positioning satellite signal sensibility to jamming and spoofing, and inertial solution's drift over time, in which the velocity and acceleration from an inertial navigation processor and an attitude and heading solution from an AHRS processor are used to aid the code and carrier phase tracking of the global positioning system satellite signals, so as to enhance the performance of the global positioning and inertial integration system, even in heavy jamming and high dynamic environments and when the GPS satellite signals are not available.

A cellular network protocol that maintains the reliability of assisted GPS based positioning is taught. An Integrity Monitor (IM) informs mobile stations, their users, or networks of measurement quality and it warns them of failing and failed GPS satellites by isolating them from the effects of these failures. Whenever an unhealthy satellite is detected, its corresponding assistance data will be excluded for delivery or for position determination. In other words, there are two specific aspects to the Integrity Monitor (IM). For DGPS users, it predicts the reliability or quality of the DGPS corrections. For all users, it isolates the mobile position calculation from the effects of GPS satellite failures. The UDRE parameter, nominally output by a reference DGPS receiver, is used to communicate the DGPS quality information, and DGPS corrections are simply excluded for failed satellites. For autonomous GPS users, a special integrity message is required and defined to communicate the satellite failure status information.

Emergency Location Transceivers (ELT) and communication transceivers (transmitters and receivers) for reception and demodulation of location finder signals, Global Positioning System (GPS) satellite signals and non GPS satellite location finder and other location finder signals. The received location finder signals are demodulated to location finder baseband signals. Baseband signal processors for processing single or a plurality of input signals for providing Orthogonal Frequency Division Multiplex (OFDM) baseband signals, filtered signals, cross-correlated shaped in-phase and quadrature-phase baseband signals and spread spectrum signals. Signal modulators for modulating the processed signals and for providing the modulated signals to the signal transmitter for transmission of the modulated signals. Emergency receiver systems for reception, demodulation and processing of the modulated transmitted signals. Certain emergency receiver embodiments, such as receivers of calls made to emergency call number 911 contain two or more receive antennas for reception and processing of the transmitted modulated signal. In certain embodiments emergency receiver systems have two or more receive antennas operated in a diversity mode, for reception and processing of the transmitted modulated signal.

A communication system for tracking an asset globally accesses multiple communication networks and switches among them, choosing the most economic, available communication mode without need for a constant power supply. An integrated motion sensor uses a combination of GPS updating and dynamic movement calculation to obtain the most reliable position estimation. Current location is identified within a small radius at all times. While taking advantage of the GPS system to obtain accurate location information, direct exposure to GPS satellites is not required at all times. The system obtains position information from GPS satellites whenever valid GPS signals are available, and provides its own location tracking capability when GPS signals are not accessible. The position accuracy of the device is preferably within a 20-meter radius from the exact location.

The invention discloses an image-processing-based unmanned plane accurate position landing method, which comprises the following steps: (1) a GPS (global position system) satellite navigation system enables an unmanned plane to be located above a ground parking apron; (2) an air pressure height measurement gauge and a distance measurement module of an ultrasound radar are combined to control the ground clearance for the unmanned plane to land; (3) a vision module identifies a coarse positioning identification domain in real time, and combines Hough Transform and RGB mean value method and gate position identification to process a coordinate of a targeted landing point; (4) when landing of the unmanned plane meets the threshold condition of the coarse positioning identification domain, the algorithm in the step (3) is utilized to perform accurate positioning treatment on the accurate positioning identification domain; and (5) the unmanned plane is controlled for accurate landing by taking the treated deviation value as the input quantity and adopting the double PID algorithm. According to the invention, the defect that insufficient GPS accuracy of the unmanned plane causes a fault landing is overcome, the intelligence for the unmanned plane control is improved, and the cost for using an accurate sensor is greatly reduced.

An inertial (“INS”) / GPS receiver includes an INS sub-system which incorporates, into a modified Kalman filter, GPS observables and / or other observables that span previous and current times. The INS filter utilizes the observables to update position information relating to both the current and the previous times, and to propagate the current position, velocity and attitude related information. The GPS observable may be delta phase measurements, and the other observables may be, for example, wheel pick-offs (or counts of wheel revolutions) that are used to calculate along track differences, and so forth. The inclusion of the measurements in the filter together with the current and the previous position related information essentially eliminates the effect of system dynamics from the system model. A position difference can thus be formed that is directly observable by the phase difference or along track difference measured between the previous and current time epochs. Further, the delta phase measurements can be incorporated in the INS filter without having to maintain GPS carrier ambiguity states. The INS sub-system and the GPS sub-system share GPS and INS position and covariance information. The receiver time tags the INS and any other non-GPS measurement data with GPS time, and then uses the INS and GPS filters to produce INS and GPS position information that is synchronized in time. The GPS / INS receiver utilizes GPS position and associated covariance information and the GPS and / or other observables in the updating of the INS filter. The INS filter, in turn, provides updated system error information that is used to propagate inertial current position, velocity and attitude information. Further, the receiver utilizes the inertial position, velocity and covariance information in the GPS filters to speed up GPS satellite signal re-acquisition and associated ambiguity resolution operations

The disclosed subject matter relates to a method for determining a Dilution of Precision Metric (DOP) with less than four satellites in a hybrid positioning system. In some embodiments, the method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, constructing a geometry matrix corresponding to the measurements from the less than four satellites using each satellite's position and the initial position estimate, multiplying the geometry matrix by its transpose to construct an H matrix, determining an inverse of the H matrix, and determining the DOP based on a sum of the diagonal elements of the inverse H matrix. In some embodiments, the non-satellite positioning system is a WLAN positioning system.

A portable electronic device, e.g., a mobile communications terminal, PDA or other handheld device, includes a GPS receiver and is configured to conduct non-GPS activities. The GPS receiver is transitioned out of a sleep state to attempt to acquire at least one GPS satellite signal responsive to a selected non-GPS activity of the device. For example, the GPS receiver may be transitioned out of the sleep state to attempt to acquire at least one GPS satellite signal responsive to a first non-GPS activity, and may be left in the sleep state notwithstanding occurrence of a second non-GPS activity. The first non-GPS activity may, for example, be associated with positioning of the device in a more conducive to reception of GPS satellite signals than the second non-GPS activity. For example, the first non-GPS activity may comprise an internet browsing activity, a video presentation activity, a gaming activity and / or a non-hands-free telephony activity.

A digital camera receives position information from GPS satellites for detecting camera position when capturing an image. Additional information, which is composed of the camera position, camera azimuth and focal distance of the taking lens, is added to image data of the captured image as tag and recorded in an image file. When the captured image is reproduced, the map image generated according to the additional information is displayed below the captured image, covering an area from the image capture point toward the subject in the captured image. Field view lines and map symbols indicating the subjects are displayed in the map image. Further, the map image includes the extension line which passes the map symbol and is extended to the subject in the captured image for showing the correspondence between the map symbol and the subject.

An object locator device is disclosed for use in conjunction with both a GPS satellite system and a two-way communication satellite. The object locating system includes a mobile unit physically connected to the object to be located. The mobile unit includes a satellite communication transceiver capable of receiving and transmitting encoded signals. A decoder is associated with the satellite communication transceiver for decoding a unique signal associated with that mobile unit and for generating an activation signal upon receipt of the unique signal. The mobile unit further includes a GPS receiver which is activated in response to the receipt of the unique signal so that the GPS receiver generates a position signal representative of the position of the mobile unit. The output signal from the GPS receiver is connected as an input signal to the satellite communication transceiver such that the satellite communication transceiver transmits the.position signal to a base station on the communication satellite. The base station physically separated from the remote unit is operable to both transmit the unique signal to the communication satellite in order to activate the mobile unit as well as for receiving the position signal from the communication satellite following activation. The base station creates a display representative of the location of the mobile unit. Preferably, this display signal is transmitted via a telephone line and modem to a computer which generates the display on a computer monitor. Energy conservation algorithms including periodic activation of the satellite communication transceiver as well as activation of the satellite communication transceiver only when the position of the mobile unit has changed more than a threshold amount between periodic signals is disclosed.

A mobile asset tracking system receives telemetry information from any number of mobile assets (e.g., railcars, truck trailers, intermodal cargo containers, etc.) transporting hazardous or non-hazardous materials. Location data is obtained through GPS satellite locks and is transmitted via a cellular module to a central database for processing. Business rules in the software of the system trigger proactive alert communications to subscribers through common communication protocols such as email, SMS text, and pagers. Personal Computers, Personal Digital Assistants (PDA's), cell phones or other common communication devices widely available to consumers may be utilized for receipt of alerts. Subscribers may be defined as manufacturers of materials, consignees who receive materials, transporters of materials (e.g. railroads, trucking companies, etc.) and communities such as county, state and / or federal emergency management personnel. GIS mapping software is utilized for geographical display of assets to authorized subscribers.

An apparatus and method for determining the position of a user terminal comprise an antenna subsystem which is able to receive signals of GPS and TV, a receiver front end which converts the frequency of the incident signals and filters out unwanted signals so that the desired signals can be sampled, a digital processing component which accommodates the imperfections of the front end and converts the measured signals into a position information. The apparatus is capable of receiving at the user terminal, broadcast television signals from television signal transmitters; determining a first set of pseudo-ranges between the user terminal and the television signal transmitters based on a known component of the broadcast television signals; receiving at the user terminal global positioning signals from a global positioning satellites; determining a second set of pseudo-ranges between the user terminal and the global positioning satellites based on the global positioning signals; and determining a position of the user terminal based on the first and second sets of pseudo-ranges, locations of the television signal transmitters, and locations of the global positioning satellites.

A system and method for assisting an integrated GPS / wireless terminal unit in acquiring one or more GPS satellite signals from the GPS satellite constellation. The invention includes a method for narrowing the PN-code phase search. That is, by accounting for the variables in geographic location and time delay relative to GPS time, the systems and methods of the present invention generate a narrow code-phase search range that enables the terminal unit to more quickly acquire and track the necessary GPS satellites, and thereby more quickly provide accurate position information to a requesting entity.

A system for locating a person including a mobile transmitter removably secured to the person and a portable monitoring unit carried by a user monitoring the location of the person. The mobile transmitter receives GPS ranging signals from GPS satellites. Each of the GPS ranging signals includes an offset proportional to the distance of the mobile transmitter from the respective GPS satellite broadcasting the GPS ranging signal. The GPS ranging signals, including the respective offsets, are transmitted to the portable monitoring unit. The portable monitoring unit comprises a GPS circuit which determines the location of the mobile transmitter based on the GPS ranging signals received by the mobile transmitter, and superimposes the location of the mobile transmitter on a map displayed on the portable monitoring unit.

Data from GPS satellites within the field of view of a ground station are retransmitted to LEO satellites, such as Iridium satellites, and cross-linked if necessary before being transmitted to a user. The user is then able to combine the fed-forward data with data received directly from GPS satellites in order to resolve errors due to interference or jamming. Iridium and data aiding thus provides a means for extending GPS performance under a variety of data-impaired conditions because it can provide certain aiding information over its data link in real time.

A mobile terminal is configured to receive wireless communications including GPS data from a terrestrial and / or satellite wireless network, and to perform pseudo-range measurements using the GPS data that is received. The mobile terminal may be configured to perform pseudo-range measurements by receiving GPS coarse / acquisition (C / A) signals from GPS satellites, estimating Doppler shifts in the received GPS C / A signals, and estimating received code phases of the GPS C / A signals using the Doppler shifts that are estimated. The estimated code phases and / or the estimated Doppler shifts of the GPS C / A signals can provide the pseudo-range measurements. By removing the Doppler shift from the received signal samples prior to performing the code phase measurement, reduced computational complexity and / or processing time may be obtained.

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.

A security system uses tags that are able to receive time signals sent from the GPS satellites or the broadcasting radio signals from the cell towers and transmit the identification and location information or signals to the central database and server for triangulation / trilateration periodically or in the event of an emergency. A security system uses tags that are able to transmit RF signals to readers located around a college campus. The tags may transmit signals periodically or in the event of an emergency. Certain locations use LF readers with exciters that trigger a signal from the tag. The security system may provide quick identification and location of individuals in danger.