Abstract: A method includes: recording an image at a sensor block, the sensor block; detecting a set of objects in the image based on an object classification model; generating a feature vector for the image based on the set of objects; accessing a workstation template for the work area, the workstation template defining a set of default objects for each workstation in the work area; identifying a subset of objects comprising an intersection of the set of default objects and the set of objects; removing the subset of objects from the feature vector; accessing an occupancy template for the work area, the occupancy template defining a set of significant objects; classifying the workstation as occupied based on the feature vector and the set of significant objects; and rendering a representation of the workstation at a work area interface, the representation indicating occupancy of the workstation.

Abstract: Systems and restaurant locations for use with a mobile ordering system, and methods thereof, to provide at least more time-efficient pick up of orders or dine-in practices by customers than with traditional ordering, pick up windows, and dine-in practices.

Abstract: A navigation satellite time system and its autonomous recovery method are provided, including a load time system, the load time system is configured to generate and maintain the load time, and the load time system comprises an space borne atomic clock, a time-frequency processing unit and a plurality of load time backups module, the time information of the load time is obtained from the ground station time; the pulse-per-second signals of the load time are generated and maintained by the space borne atomic clock and the time-frequency processing unit; when the time-frequency processing unit fails, the first-level recovery state is triggered: the time-frequency processing unit compares the time information and the pulse-per-second signals reversely output by the multiple load time backup modules to perform load time recovery.

Abstract: A method can include receiving sensor data, receiving satellite observations, determining a positioning solution (e.g., PVT solution, PVA solution, kinematic parameters, etc.) based on the sensor data and the satellite observations. A system can include a sensor, a GNSS receiver, and a processor configured to determine a positioning solution based on readings from the sensor and the GNSS receiver.

Abstract: A system includes a vehicle and a vehicle control system configured to autonomously control one or more operations of the vehicle. The system also includes a navigation receiver configured to identify a location of the vehicle and to provide the identified location to the vehicle control system. To identify the location of the vehicle, the navigation receiver is configured to identify whether navigation signals received by the navigation receiver are spoofed based on angles of arrival for the navigation signals and to suppress any of the navigation signals determined to be spoofed. The navigation receiver may be configured to suppress any of the navigation signals determined to be spoofed in order to prevent an illicit actor from misdirecting the vehicle to an undesired location and/or to prevent an illicit actor from causing the vehicle to make course corrections based on an incorrect current location of the vehicle.

Abstract: This application discloses a positioning data processing method performed at a computing device. The method includes: obtaining a first positioning data sequence generated by a moving target chronologically; performing filtering processing on the first positioning data sequence according to a preset filtering algorithm to obtain a filtered data sequence, and performing adsorption calculation on the filtered data sequence to obtain an adsorption data sequence, the preset filtering algorithm being an algorithm obtained after a Kalman filtering algorithm is corrected according to the adsorption data sequence; outputting the filtered data sequence to obtain a second positioning data sequence of the moving target; and displaying a position corresponding to second positioning data in the second positioning data sequence.

Abstract: A PVT calculation device includes a memory; and one or more processors in communication with the memory configured to perform operations including: receiving observations and ephemerides from satellites to obtain PVT data of the satellites and predicted PVT results of the receiver; setting up observation functions respectively corresponding to the satellites; calculating by a least square solution first estimated PVT results of the receiver based on the observation functions; iteratively eliminating by a Random-Sampling Iterative Kalman Filter (RSIKF) algorithm fault observation functions from the observation functions in an inner cluster until no fault observation functions detected in the inner cluster; calculating by the RSIKF algorithm a second estimated PVT results of the receiver using the observation functions in the inner cluster; and outputting final estimated PVT results of the receiver. The PVT calculation device may calculate the PVT results of the receiver with improved accuracy and stability.

Abstract: This application provides an example satellite, an example terminal device, an example satellite communication system, and an example satellite communication method. One example satellite communication method includes obtaining, by a first satellite, at a media access control (MAC) layer, data and/or signaling, where the first satellite is a low orbit satellite. When MAC-layer first processing needs to be performed on the data and/or the signaling, performing, by the first satellite, the MAC-layer first processing on the data and/or the signaling. The MAC-layer first processing includes at least one of hybrid automatic repeat request (HARQ) function processing or random access (RA) function processing.

Abstract: In some embodiments, space objects may be detected within shortwave infrared (SWIR) images captured during the daytime. Some embodiments include obtaining a stacked image by stacking shortwave infrared (SWIR) images. A spatial background-difference image may be generated based on the stacked image, and a matched-filter image may be obtained based on the spatial background-difference image. A binary mask may be generated based on the matched-filter image. The binary mask may include a plurality of bits each of which including a first value or a second value based on whether a signal-to-noise ratio (SNR) associated with that bit satisfies a threshold condition. Output data may be generated based on the spatial background-difference image and the binary mask, where the output data provides observations on detected space objects in orbit.

Abstract: Systems and methods for implementing single differences within a solution separation framework are provided. In certain embodiments, a method includes processing pseudorange measurements to determine a full navigation solution by applying a single difference between the pseudorange measurements. The method additionally includes performing innovation sequence monitoring. Also, the method includes processing a subset of the pseudorange measurements to determine a set of navigation sub-solutions by applying a single difference between the pseudorange measurements, wherein a result of the innovation sequence monitoring is applied to the set of navigation sub-solutions; and providing faults detection and computing protection levels of quantities of navigation information based on a full navigation solution estimate, navigation sub-solution estimates, dependence among the full navigation solution and the set of navigation sub-solutions, and probabilities of missed detection and false alert.

Abstract: A method comprises: obtaining a GPS measurement; obtaining a first IMU measurement; obtaining a second IMU measurement; applying a first particle filter to the GPS measurement and the first IMU measurement to obtain a first position solution; applying a second particle filter to the GPS measurement and the second IMU measurement to obtain a second position solution; calculating a first sensor weight of the first position solution based on a likelihood function; calculating a second sensor weight of the second position solution based on the likelihood function; resampling the first position solution based on the first sensor weight to obtain a first resampled position solution; resampling the second position solution based on the second sensor weight to obtain a second resampled position solution; and calculating a final position estimate based on the GPS measurement, the first resampled position solution, and the second resampled position solution.

Abstract: A beam splitting hand off systems architecture and method for using the same are disclosed. In one embodiment, the method comprises: generating a first beam with a single electronically steered flat-panel antenna to track a first satellite; generating a second beam with the single electronically steered flat-panel antenna to track a second satellite simultaneously while generating the first beam to track the first satellite; and handing off traffic from the first satellite to the second satellite.

Abstract: Example navigation aids for increasing the accuracy of a navigation system are disclosed herein. An example method disclosed herein identifying, with an aircraft intent description language (AIDL) aid, an AIDL instruction as associated with a first dynamic activity level of a plurality of dynamic activity levels and determining, with the AIDL aid, an aircraft state to be affected by the AIDL instruction. The example method also includes changing, with a navigation filter, a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft and estimating, with the navigation filter, a trajectory of the aircraft based on the weighting scheme and the measurement.

Abstract: Systems and methods are described herein for multi-mode compensation of frequency errors within signals transmitted and received by a mobile terminal. The frequency error can be due to Doppler shift and oscillator error, which introduce opposite frequency shifts. In an acquisition mode, the mobile terminal initially compensates for the oscillator error while transmitting a signal to a communication system that contains the Doppler shift. Upon receiving a message from the communication system indicating the Doppler shift contained in the transmit signal, the mobile terminal can then switch to a tracking mode that can compensate for both Doppler shift and oscillator error.

Abstract: Example navigation aids for increasing the accuracy of a navigation system are disclosed herein. An example method disclosed herein identifying, with an aircraft intent description language (AIDL) aid, an AIDL instruction as associated with a first dynamic activity level of a plurality of dynamic activity levels and determining, with the AIDL aid, an aircraft state to be affected by the AIDL instruction. The example method also includes changing, with a navigation filter, a weighting scheme for a measurement of the aircraft state obtained by an inertial navigation system (INS) of the aircraft and estimating, with the navigation filter, a trajectory of the aircraft based on the weighting scheme and the measurement.

Abstract: Disclosed in the present invention are a data transmission method, an apparatus and an antenna array, in order to realize wide bandwidth data transmission of massive antenna array.

Abstract: A satellite radio wave receiving processing unit 60 includes a front end 60a which receives a radio wave including a code signal transmitted from a satellite, and a baseband unit 64 which acquires the code signal from the received radio wave, in which the baseband unit identifies a pseudo-random code sequence used for performing spread spectrum to the code signal and a phase of the pseudo-random code sequence in a transmission period, identifies a code type of the code signal every time according to the transmission period, identifies, by comparing an array of the identified code type with a plurality of comparison arrays expected to appear as the array of the code type, a head timing of each code in the code signal according to a comparison array in which a result of the comparison satisfies a predetermined condition, and identifies each code in synchronization with the identified head timing.

Abstract: A satellite signal receiver has a positioning error in a range from ?8 m to +8 m with a probability equal to or more than 95% when positioning in a reception environment with a signal strength equal to or more than ?135 dBm and average power consumption from start of positioning to first positioning equal to or less than 7 mW.

Abstract: A global navigation satellite system (GNSS) receiver includes a processor to determine whether a first satellite is in view of GNSS receiver; whether a second satellite is in view of GNSS receiver when first satellite is in view of GNSS receiver; and whether a third satellite is in view of GNSS receiver when first satellite is not in view of GNSS receiver. Second satellite was previously determined more likely to be in view when first satellite is in view based on a first average distance between first satellite and second satellite based on a first orbit of first satellite and a second orbit of second satellite. Third satellite was previously determined more likely to be in view when first satellite is not in view based on a second average distance between first satellite and third satellite based on first orbit of first satellite and a third orbit of third satellite.

Abstract: A satellite signal tracking method performed by a receiver that receives a satellite signal from a positioning satellite, the satellite signal tracking method including: computing a first Doppler frequency using a received signal obtained by receiving the satellite signal, computing a second Doppler frequency using the first Doppler frequency and a signal from the sensor unit including at least an acceleration sensor, and acquiring the satellite signal using the second Doppler frequency.

Abstract: Method and apparatuses involving satellite position signals are disclosed. Based on data indicating a usage environment, parameters, for example acquisition parameters or calculation parameters, are adapted.

Abstract: Method of determining navigation parameters for a carrier by a hybridization device comprising a Kalman filter (3) formulating a hybrid navigation solution on the basis of inertial measurements calculated by a virtual platform (2) and of raw measurements of signals emitted by a constellation of satellites delivered by a satellite positioning system (GNSS), characterized in that it comprises, the steps of: —determination, for each satellite, of at least one likelihood ratio (Ir, Ir?) between a hypothesis regarding a fault of a given nature of the satellite and a hypothesis regarding an absence of fault of the satellite, —declaration, of a fault of a given nature on a satellite as a function of the likelihood ratio (Ir, Ir?) associated with this fault and of a threshold value, —estimation of the impact of the declared fault on the hybrid navigation solution, and ?correction of the hybrid navigation solution as a function of the estimation of the impact of the declared fault.

Abstract: Systems and methods for extracting synchronization information from ambient signals, such as broadcast television signals, and using the synchronization information as a reference for correcting the local time base so that a GNSS positioning receiver system maintains relative time base accuracy with respect to a GNSS time.

Abstract: Inventive aspects include a method, apparatus, and system for reducing power consumption in GNSS receivers. Such may include receiving timing and accuracy parameters, processing pre-positioning information in preparation for signal acquisition or signal track, determining whether a plurality of satellites are in-view, applying an ON signal to one or more components of an analog signal processing section and to one or more components of a digital signal processing section, and within a dynamic time window, acquiring signals of the plurality of in-view satellites and simultaneously applying, in real-time, signal sensing logic to the acquired signals, until determining that a position fix of the electronic receiver is obtained. Responsive to the determination that the position fix is obtained, an OFF signal may be applied to the one or more components of the analog signal processing section and to the one or more components of the digital signal processing section.

Abstract: A method determines the atmospheric refraction of a radar beam by utilizing a stabilized optical telescope directed toward a star near the radar target location. This allows measuring the target refraction as observed from ships at sea without a-priori knowledge of the local refraction index or weather conditions in the target area. The telescope may employ an infra-red (IR) sensor and is capable of imaging stars. The atmospheric refraction of the star light is determined by pointing the telescope based on star ephemeris data, and measuring the star image deviation from the center of the telescope's field-of-view (FOV). The corresponding refraction of the radar beam can be determined by employing a conversion factor relating the IR-to-RF atmospheric propagation characteristics. This conversion factor can be obtained by dedicated tracking measurements.

Abstract: The present invention provides methods of performing GNSS receivers' satellite signal acquisition and TTFF while taking advantage of SBAS signals. Due to a SBAS satellite's geostationary position and typically strong signal, the SBAS satellite signal can be acquired more quickly than a GPS satellite signal. Once a SBAS satellite signal is acquired the Doppler frequency search uncertainty may be reduced for remaining GNSS satellites which are to be acquired. Furthermore, a satellite search list may be optimized to search for satellites close to the line of sight (LOS) of the SBAS satellite for which a signal has been acquired, in receiver “warm” and “hot” start modes. Moreover, since a SBAS signal sub-frame is only one second long, which is shorter than six seconds for a GPS signal sub-frame, synchronization of the SBAS signal sub-frame may be achieved faster than for GPS signals. With aided time information, a receiver may compute the absolute time of week (TOW) from a sub-frame synchronized SBAS signal.

Abstract: The present invention provides apparatus and methods for improving satellite navigation by assessing the dynamic state of a platform for a satellite navigation receiver and using this data to improve navigation models and satellite tracking algorithms. The dynamic state of the receiver platform may be assessed using only accelerometer data, and does not require inertial navigation system integration. The accelerometers may not need to be very accurate and may not need to be aligned and/or accurately calibrated.

Abstract: A GNSS receiver reduces the time to first fix by utilizing the properties of existing radiated signals of opportunity, such as AM or FM radio signals, television signals and so forth, to reduce the uncertainties associated with oscillator frequency and phase, and further utilizing an Almanac and battery backed-up date and time to determine the satellites in view and reduce the uncertainties associated with Doppler. The receiver may use multiple signals of opportunity to determine the city or local area in which the receiver is located based on the set of frequencies of the signals, and also to reduce search uncertainties for oscillator frequency by estimating an offset based on the differences between the frequencies of the respective signals of opportunity at the receiver and the nominal broadcast frequencies of the signals.

Abstract: A mobile communication device includes a global navigation satellite system (GNSS) receiver for receiving GNSS signals, a radio frequency (RF) receiver for receiving RF signals and a voltage controlled oscillator supplying an oscillator signal to the GNSS receiver and the RF receiver. The GNSS receiver and the RF receiver use the oscillator signal to receive the GNSS signals and the RF signals. The mobile communication device also includes a processor for initializing and/or adjusting a model of a frequency behavior of the voltage controlled oscillator, and uses the model to track the GNSS signals when computing a location of the mobile communication device.

Abstract: The present system relates to a GNSS receiver that includes a processor. The processor is configured to receive a temperature signal from a temperature sensor indicating an operating temperature of an resonator. The processor is also configured to compute a frequency and a frequency correction data of the resonator based on the temperature and a frequency model of the resonator. The processor then transmits the frequency correction data to an RF receiver which utilizes the frequency correction data and the resonator to receive and RF signal.

Abstract: The present invention discloses a radio beacon coupled to an altimeter, for GPS positioning in an elevator, configured to broadcast signals forcing a nearby GPS receiver to read constant latitude and constant longitude, associated with the position of the elevator shaft, and altitude associated with the altimeter reading. The acquired in-elevator position can serve as an initial fix for further navigation, particularly indoors.

Abstract: A low-cost GPS/GNSS receiver receives a satellite signal at an RF frequency (fRF). The GPS/GNSS receiver includes a front end section for receiving the satellite signal and generating a digital complex signal having a first bandwidth, the received satellite signal being converted into a complex signal before digitizing, a signal capturing section for searching for and acquiring the satellite signal, the signal capturing section including a capture memory, a baseband processor for tracking the acquired satellite signal, and a signal splitter coupled to the front end section. The signal splitter splits the digital complex signal into two bandwidths, by generating a narrowband digital complex signal having a second bandwidth substantially smaller than the first bandwidth. The signal splitter provides the narrowband digital signal to the capture memory and the wider first bandwidth digital complex signal to the baseband processor.

Abstract: Embodiments of the invention provide a method of detecting movement to aid GNSS receivers. By detecting when the user is stationary, the Doppler frequency estimation can be corrected or the SNR can be boosted more both of which lead to improved performance. The embodiments allow a GNSS receiver to process signals in when the signal level would otherwise be too low—for example indoors. The embodiments can improve performance when one or more satellites are temporarily blocked but one or more satellites are still being tracked.

Abstract: Provided is a system for collecting and managing rainfall attenuation data and rainfall intensity data in a satellite communication system. The system may include: a satellite transmitter to transmit a satellite beacon signal; a Global Positioning System (GPS) to transmit a GPS signal; at least one data collecting apparatus to generate rainfall attenuation data about the satellite beacon signal when the satellite beacon signal is received from the satellite transmitter, and to generate rainfall intensity data within a valid path length of rainfall attenuation, to extract time information from the GPS signal, and to assign the time information to the rainfall attenuation data and the rainfall intensity data; and a data managing apparatus to receive, from the at least one data collecting apparatus, the rainfall attenuation data and the rainfall intensity data assigned with the time information, and to manage the received rainfall attenuation data and rainfall intensity data.

Abstract: Embodiments related to cross-talk mitigation are described and depicted.

Abstract: Flight management systems can behave erratically when the distance measurements on which they are based are subject to value jumps because they liken these value jumps to movements of the aircraft performed at speeds exceeding the performance levels of the aircraft for which they were designed. To avoid this, the proposed flight management system uses a filter to spread the distance value jumps in time, over periods of the order of those needed for the aircraft to come through the distance differences that they represent. This filter replaces a value jump with a ramp making up the difference and corresponding to a movement that remains within the performance scope of the aircraft.

Abstract: An active GPS tracking system and method includes a user setting interface for receiving a reporting distance, a distance trigger module, a GPS module and a wireless communication module. The distance trigger module calculates a moving distance of the active GPS tracking system, and generates and sends an interrupt signals to the GPS module to make it enter a working mode when the moving distance is greater than or equal to the reporting distance. Then, the GPS module determines a current position of the active GPS tracking system and determines whether an actual displacement is greater than or equal to the reporting distance to determine if reporting the current position. If the actual displacement is greater than or equal to the reporting distance, the wireless communication module receives the current position from the GPS module, and reports to a monitor center.

Abstract: A method of acquiring a signal includes generating a first set of acquired signal power values comprising an acquired signal power value for each of a plurality of Doppler bins over a first predetection integration time (PIT) interval, and generating a second set of acquired signal power values comprising an acquired signal power value for each of the plurality of Doppler bins over a second subsequent PIT interval. The first and the second sets are used to generate at least three additional sets of acquired signal power values. A new set is generated by selecting the maximum of the summations for each Doppler bin from the three additional sets, and a Doppler shift is identified from the Doppler bin having the maximum summation value. The output may be used to initialize a first and a second extended Kalman filters for tracking a carrier signal and a code signal, respectively.

Abstract: A receiver for continuous carrier phase tracking of low carrier-to-noise ratio (“CNR”) signals from a plurality of radio navigation satellites while the receiver is mobile. The receiver may have: a radio frequency (RF) front-end that provides satellite data corresponding to signals received from the plurality of radio navigation satellites; an inertial measurement unit (IMU) that provides inertial data; and a processor circuit in circuit communication with the RF front end and the IMU, the processor circuit being capable of using satellite data from the RF front-end and inertial data from the IMU to perform continuous carrier phase tracking of low CNR radio navigation satellite signals having a CNR of about 20 dB-Hz, while the receiver is mobile. The receiver may be a GPS receiver for continuous carrier phase tracking of low-CNR GPS signals.

Abstract: Method and apparatus for processing satellite signals in an SPS receiver is described. In one example, the satellite signals are correlated against pseudorandom reference codes to produce correlation results. A determination is made whether the SPS receiver is in a motion condition or a stationary condition. The correlation results are coherently integrated in accordance with a coherent integration period. The coherent integration period is a value that depends upon the motion condition of the SPS receiver.

Abstract: A method and apparatus for estimating oscillator signal variation due to temperature and for providing an estimated frequency to a GPS receiver in order to assist the GPS receiver to acquire the signals quickly is disclosed. A temperature sensor is closely thermally coupled with the crystal oscillator in the GPS receiver and during GPS tracking mode, when the error in the oscillator signal is known with precision, outer bounds of TCXO frequency at given temperatures are maintained, which may correspond to rising and falling temperature conditions. During acquisition mode, an estimated frequency value is provided to the GPS receiver based on a determined average of these bounds. Optionally, an uncertainty factor associated with the frequency estimated may also be provided. The two bounds take into account the hysteresis effects of the oscillator signal drift due to temperature so that a more accurate initial frequency estimate can be provided to the GPS receiver, thus reducing its average time to first fix.

Abstract: The invention relates to an inertia GNSS navigation System linked to a vehicle comprising: a set of acquisition units of sensor data each delivering sensor data in digital form, a unit for processing sensor data (30) configured to exploit digital data delivered by said set of acquisition units and to plot a status vector of the dynamics of the vehicle, and in which the set of acquisition units of sensor data comprises: a unit for acquiring and digitising GNSS signals (20) comprising an antenna structure (RA) configured to receive GNSS signals and an analog-digital converter (2) coupled to the antenna structure and configured to deliver GNSS signals in digital form to the unit for processing sensor data an inertial measuring unit (6) configured to deliver inertial data originating from inertial sensors in digital form to the unit for processing sensor data.

Abstract: A method and apparatus for qualifying a Satellite Positioning System (SPS) location determination. A method in accordance with the present invention comprises determining a constellation of satellites used in the location determination, making a measurement set based on signals received from the constellation of satellites, comparing the measurement set and the constellation of satellites used in the location determination to a predetermined threshold, and reporting the location determination only when the threshold is not exceeded. Such a method further optionally includes the threshold being user-selectable, the threshold being adjusted or disabled based on a pre-defined scheme, the threshold being adjusted in a sequential form based on a pre-defined scheme, and the measurement set being made in a Global Positioning System (GPS) receiver.

Abstract: In at least some embodiments, an electronic device includes a navigation system receiver and a receiver motion estimator coupled to the navigation system receiver. The receiver motion estimator determines and provides a receiver motion estimation to the navigation system receiver to reduce complexity of a satellite signal search operation performed by the navigation system receiver.

Abstract: A mobile station determines an approximate latitude using a measured feature of the Earth's magnetic field. An approximate longitude may also be determined. The mobile station uses the approximate latitude and longitude, if determined, to assist in determining a position fix for the mobile station, e.g., by determining a list of visible satellites in a satellite positioning system (SPS) during search and acquisition of satellite signals and/or using the approximate position as a seed position in the position computation. The feature of the Earth's magnetic field may be, e.g., inclination or vertical intensity, and may be determined using data from a three-dimensional magnetometer and a three-dimensional accelerometer. An instantaneous value of the magnetic field feature may be averaged to reduce the affects of motion and the presences of large metallic masses.

Abstract: Various systems, methods and devices are implemented for processing received signals. Consistent with one such embodiment, a method is implemented for use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms. The method involves interpreting a received signal using space time adaptive processing (STAP). A convergence speed of the adaptive algorithms is set based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop. A carrier-phase de-rotation constraint is implemented into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.

Abstract: A final located position when a GPS receiver section (positioning section) has finished positioning is determined to be the latest located position, and the combination of identification information (ID) of base stations (suspended base stations) with which a portable telephone wireless communication circuit section has performed wireless communication is stored in a flash ROM. The combination of base stations that currently perform wireless communication with the wireless communication section and the combination of the suspended base stations stored in the flash ROM are compared when the GPS receiver section again performs positioning. When it has been determined that the combinations coincide, the latest located position stored in the flash ROM is estimated to be the present position of a portable telephone. The estimated present position is used as the initial position during the first positioning when the GPS receiver section again performs positioning.

Abstract: Systems and methods of providing precision locations for sensors which make up an array of sensors in a gunshot detection system. Consistent with some exemplary implementations, sensors may employ a commercial GPS which reports a sensor position or a group of pseudoranges to GPS satellites. A server may collect differential information from a differential node and, in one exemplary implementation, may calculate a precision position for each sensor by adjusting the reported position or pseudoranges with the differential information. In other exemplary implementations, differential information may be sent from the host to individual sensors which calculate their own precision positions. Exemplary differential information may include latitude and longitude corrections, pseudorange corrections, ionospheric delay, GPS satellite clock drift, or other corrective term which will improve the accuracy of a sensor position.