Abstract: A method and apparatus for improving a dead reckoning estimate of a mobile unit is described. When an accurate position cannot be determined for a mobile unit, for example if GPS is unavailable, a dead reckoning estimate can be improved when two or more mobile units share their position estimates and the shared position estimates are used with either the range between the two units or knowledge that the units are within a threshold distance of each other to refine the position estimate of at least one unit.

Abstract: Systems, devices, and methods for a vertical take-off and landing (VTOL) aerial vehicle having a first GPS antenna and a second GPS antenna, where the second GPS antenna is disposed distal from the first GPS antenna; and an aerial vehicle flight controller, where the flight controller is configured to: utilize a GPS antenna signal via the GPS antenna switch from the first GPS antenna or the second GPS antenna; receive a pitch level of the aerial vehicle from the one or more aerial vehicle sensors in vertical flight or horizontal flight; determine if the received pitch level is at a set rotation from vertical or horizontal; and utilize the GPS signal not being utilized via the GPS antenna switch if the determined pitch level is at or above the set rotation.

Abstract: Systems and methods of heading determination with global navigation satellite system (GNSS) signal measurements are provided herein. A pair of antennas may be separated by a known baseline length and mounted on a vehicle. A GNSS receiver may obtain pseudorange and carrier phase measurements for GNSS satellites within view. An LRU may estimate carrier phase ambiguities and a two-dimensional vector, using the known baseline length and a linearized measurement model. The LRU may determine integer ambiguities using the estimated carrier phase ambiguities. The LRU may determine assumed wrong fixes of the integer ambiguities and a probability of almost fixed value. The LRU may store the set of integer ambiguities. The LRU may determine, from accumulated data over measurement epochs, updated integer ambiguities. The LRU may correct the carrier phase measurements using the updated integer ambiguities. The LRU may compute the heading using the corrected carrier phase measurements.

Abstract: Systems, devices, and methods for a vertical take-off and landing (VTOL) aerial vehicle having a first GPS antenna and a second GPS antenna, where the second GPS antenna is disposed distal from the first GPS antenna; and an aerial vehicle flight controller, where the flight controller is configured to: utilize a GPS antenna signal via the GPS antenna switch from the first GPS antenna or the second GPS antenna; receive a pitch level of the aerial vehicle from the one or more aerial vehicle sensors in vertical flight or horizontal flight; determine if the received pitch level is at a set rotation from vertical or horizontal; and utilize the GPS signal not being utilized via the GPS antenna switch if the determined pitch level is at or above the set rotation.

Abstract: An apparatus includes a controller coupled to at least two antennas and one or more sensors. An initial azimuth value for the apparatus is determined based on output of the one or more sensors. Respective phase differences between satellite signals received from respective satellites at the at least two antennas are detected, and respective phase difference values for the respective satellites are calculated based on the initial azimuth value, a distance between the at least two antennas in the apparatus, and positions of the respective satellites. An actual azimuth angle of the apparatus is identified based on the initial azimuth value from the output of the one or more sensors and variations between the respective detected phase differences and the respective calculated phase difference values for the respective satellites.

Abstract: System for estimating carrier phases, including a receiver that receives radio signals from satellites; the radio signals are converted into digital signals; a plurality of channels, each including a correlator receives digital signals and outputs (I, Q) components for one satellite; a reset accumulator that receives (I, Q) components, accumulates them over multiple cycles of a pseudorandom code and outputs accumulated (Is, Qs); a discriminator that generates a tracking error signal; a CCLF (common controlled loop filter) receives the tracking error signal and outputs a frequency control signal and a phase control signal; NCO receives the frequency and phase control signals, and outputs a reference signal. CCLF also receives correction signals based on the radio signals due to shock, vibration or acceleration. NCO control signals depend on the correction signals due to a change in an effective bandwidth of the CCLF to reduce coordinate measurement dynamic distortions.

Abstract: A method and apparatus for improving a dead reckoning estimate of a mobile unit is described. When an accurate position cannot be determined for a mobile unit, for example if GPS is unavailable, a dead reckoning estimate can be improved when two or more mobile units share their position estimates and the shared position estimates are used with either the range between the two units or knowledge that the units are within a threshold distance of each other to refine the position estimate of at least one unit.

Abstract: A system and method to obtain vehicle positional information as it is traveling. The method of generating a vehicle path includes obtaining a first position of a vehicle; monitoring an occurrence of a positional trigger event; after the occurrence of the positional trigger event, obtaining a second position of the vehicle; and transmitting the first and second positions to a storage device wherein the first and second positions form the path. The disclosure also provides for a system to generate the path of the vehicle. The system includes a vehicle system module configured to perform the various steps described herein.

Abstract: A system for providing near real time navigation information includes a first communication device configured to transmit collection vessel data representing collection vessel draft and a geoposition. It also includes a second communication device configured to transmit user vessel data, including user vessel draft and user geoposition. A processing device is configured to determine a keel verified depth (KVD) based upon the collection vessel depth for the geoposition and transmit that data to the second communication device.

Abstract: Systems that enable observing celestial bodies during daylight or in under cloudy conditions.

Abstract: Systems and methods to monitor for false alarms from ionosphere gradient monitors are provided. In one embodiment, a method for mitigating false gradient alarms in a satellite navigation Ground Based Augmentation System (GBAS) ground station comprising a plurality of satellite navigation system reference receivers comprises: generating an alarm signal with an ionosphere gradient monitor (IGM) at the GBAS ground station; determining whether the alarm signal is a false alarm based on data derived from carrier phase measurements received from the plurality of satellite navigation system reference receivers; and blocking the alarm signal for at least a first duration of time based on the determining.

Abstract: A position detector which detects the position of a movable member relative to a fixed member includes a signal detector configured to detect periodic signals which respectively indicate predetermined values concerning the position of the movable member relative to the fixed member and change at different periods in accordance with a position change, a signal processor configured to generate displacement signals based on the periodic signals detected by the signal detector and sequentially output the generated displacement signals while switching the signals at a predetermined period, a position calculator configured to calculate a position of the movable member relative to the fixed member based on the displacement signals, and a reliability determining unit configured to determine that the reliability of the position calculated by the position calculator is low, if the displacement amount of the movable member in the predetermined period is larger than a predetermined threshold.

Abstract: In a positioning system, an arithmetic processor analyzes positioning data acquired by a receiving terminal and determines a positioning target location. Upon reception of positioning data, the arithmetic processor accumulates the positioning data on analysis data stored in a storage section prior to the reception, stores an accumulated data as new analysis data, and transmits an analysis result to the receiving terminal. The receiving terminal transmits positioning data, acquired for a predetermined time, to the arithmetic processor and continues to acquire positioning data. Upon reception of the analysis result, the receiving terminal determines whether the analysis result is good or poor. When the analysis result is poor and the positioning data is stored for the predetermined time from a last transmission of the positioning data, the receiving terminal transmits the positioning data to the arithmetic processor and continues to acquire positioning data.

Abstract: A method, system, and device are provided for transmitting emergency calls by means of a mobile device via a speech channel and a data channel. The data channel serves to transmit location information. The location information may be transmitted in encoded form. The information also may be transmitted via the speech channel. The information may then be compared for consistency in the service center.

Abstract: Methods and apparatus are described for processing a set of GNSS signal data derived from code observations and carrier-phase observations at multiple receivers of GNSS signals of multiple satellites over multiple epochs, the GNSS signals having at least two carrier frequencies and a navigation message containing orbit information, comprising: obtaining precise orbit information for each satellite, determining at least one set of ambiguities per receiver, each ambiguity corresponding to one of a receiver-satellite link and a satellite-receiver-satellite link, and using at least the precise orbit information, the ambiguities and the GNSS signal data to estimate a phase-leveled clock per satellite.

Abstract: This disclosure relates to the use of a method for determining communication timing of an aerial vehicle, such as a balloon. The method includes determining a trajectory of an aerial vehicle. Additionally, the method includes, based on the trajectory, determining a transmission trigger for a location-report message such that a location-report message transmission that is responsive to the transmission trigger has at least a predefined probability of occurring before the aerial vehicle contacts the ground. Further, the method also includes, responsive to the transmission trigger, transmitting the location-report message, where the location-report message comprises location data from the aerial vehicle.

Abstract: A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.

Abstract: A computer-implemented method for analyzing travel patterns in transit systems is provided. The method includes identifying an existing transit point of a transit system and receiving location information including geo-location paths of a plurality of mobile devices. Each of the geo-location paths includes the identified transit point. The method also includes determining a proposed transit point for the transit system based on the geo-location paths of the received location information. Systems and machine-readable media are also provided.

Abstract: The present invention relates to a system for resolving phase ambiguities in phase rate of change (PROC) measurements of a long baseline interferometer (LBI). The system includes an LBI having a first antenna and a second antenna positioned on a vehicle to receive the RF signal transmitted by the RF emitter, and a processor positioned on the vehicle. The processor is configured to determine a first phase rate of change (PROC) of the RF signal received by the LBI over a short time interval to produce a short time interval range estimate of the RF emitter, determine a second PROC of the RF signal received by the LBI over a long time interval which is greater than the short time interval, to produce a plurality of ambiguous long time interval range estimates of the RF emitter, and c) select one of the plurality of long time interval range estimates based on the short time interval range estimate.

Abstract: A vehicle control system having a controller and a spatial database adapted to provide spatial data to the controller at control speed. The spatial data provided from the spatial database to the controller includes images collected from an optical sensor subsystem in addition to other data collected by a variety of sensor types, including a GNSS or inertial measurement system. The spatial data received by the controller from the database forms at least part of the control inputs that the controller operates on to control the vehicle. The advantage provided by the present invention allows control system to “think” directly in terms of spatial location. A vehicle control system in accordance with one particular embodiment of the invention comprises a task path generator, a spatial database, at least one external spatial data receiver, a vehicle attitude compensation module, a position error generator, a controller, and actuators to control the vehicle.

Abstract: A multi-antenna GNSS system and method provide earth-referenced GNSS heading and position solutions. The system and method compensate for partial blocking of the antennas by using a known attitude or orientation of the structure, which can be determined by an orientation device or with GNSS measurements. Multiple receiver units can optionally be provided and can share a common clock signal for processing multiple GNSS signals in unison. The system can optionally be installed on fixed or slow-moving structures, such as dams and marine vessels, and on mobile structures such as terrestrial vehicles and aircraft.

Abstract: A GNSS receiver utilizes an antenna structure that two or more antennas that are spaced apart from their neighboring antennas by less than 1 wavelength of a GNSS satellite carrier signal of interest. The receiver calculates the orientation of the antennas directly from differences in the carrier phase angles measured at the two antennas, without resolving integer carrier cycle ambiguity.

Abstract: A system for generating and utilizing a look-up mechanism consisting of one or more phase difference error maps, tables and/or mathematical models calculates the respective maps, tables and/or models by placing a short baseline or ultra-short baseline antenna array in a known location and known orientation, determining angles of incidence of incoming GNSS satellite signals with respect the antenna array and calculating expected carrier phase differences between respective pairs of antennas, calculating measured carrier phase differences between the respective pairs of antennas, and determining carrier phase difference errors using the expected and measured carrier phase differences. The carrier phase difference errors are then recorded in the look-up mechanism, with the maps and, as appropriate, look-up tables for the respective pairs of antennas being indexed by angles of incidence. Thereafter, the system utilizes the look-up mechanism when determining the unknown orientation of the antenna structure.

Abstract: A system for location based services utilizing a mobile device includes a software module configured to operate in a background mode on the mobile device. The software module is further configured to determine a geographical location of the mobile device and transmit the geographical location at predetermined intervals. A services platform is in communication with the mobile device for receiving the geographical location. The services platform includes at least one location based service module for facilitating at least one location based service on the mobile device. A plurality of back end databases is in communication with the services platform where the services platform integrates data from the back end databases with data from a location database. A secure website is included where an owner of the mobile device can view the geographical location of the mobile device and geographical locations of other mobile devices and have the ability to view friends/family/business associates on their mobile device.

Abstract: System and method for determining the roll rate and roll angle of a spinning platform. The IQ amplitude and/or phase characteristics of GPS signals received at a single receiver antenna are measured using the signals output directly by a correlator that is driven at the satellite tracking frequency used for forming the navigation solution. The roll rate and roll angle are determined in real time by a Roll filter, which is preferably an Extended Kalman Filter (EKF) employing probabilistic data association, whose inputs include the measured IQ characteristics and the navigation solution. Data from non-GPS measurement sources is optionally provided to update the navigation and/or roll solution.

Abstract: An optical tracking vehicle control system includes a controller adapted for computing vehicle guidance signals and a guidance subsystem adapted for receiving the guidance signals from the controller and for guiding the vehicle. An optical movement sensor is mounted on the vehicle in optical contact with a travel surface being traversed by the vehicle. The optical movement sensor is connected to the controller and provides vehicle movement signals thereto for use by the controller in computing vehicle position. The optical movement sensor can be either mounted on a gimbal for movement independent of the vehicle, or, alternatively, multiple optical movement sensors can be provided for detecting yaw movements. GNSS and inertial vehicle position tracking subsystems are also provided. Still further, a method of tracking a vehicle with an optical movement sensor is provided.

Abstract: A method and apparatus for estimating a location of a device. For each of a plurality of locations of a device, a set of positional data is determined from signals received from a plurality of satellites. The positional data is filtered and compared with data from a road network database. This comparison may be a function of a distance from at least one point defined by a set of the filtered positional data to a road in the road network database and an angle between a line representing a best fit for plural points defined by corresponding plural sets of the filtered positional data to a line defined by a road in the road network database.

Abstract: A system and method for determining the roll rate and roll angle of a spinning platform, using the measured phase differences between the GPS satellite signals received on two or more antennas. The measured phase differences and the navigation solution from a GPS receiver are processed in a Kalman filter to obtain the desired information. Data from non-GPS measurement sources is optionally provided to update the navigation solution. Although of wide applicability, the invention is uniquely suited to the measurement of roll rates and roll angles of fast spinning platforms with small baselines, in which the antennas are separated from each other by distances that are a fraction of the GPS signal wavelength.

Abstract: A GNSS receiver utilizes an antenna structure that two or more antennas that are spaced apart from their neighboring antennas by less than 1 wavelength of a GNSS satellite carrier signal of interest. The receiver calculates the orientation of the antennas directly from differences in the carrier phase angles measured at the two antennas, without resolving integer carrier cycle ambiguity.

Abstract: An optical tracking vehicle control system includes a controller adapted for computing vehicle guidance signals and a guidance subsystem adapted for receiving the guidance signals from the controller and for guiding the vehicle. An optical movement sensor is mounted on the vehicle in optical contact with a travel surface being traversed by the vehicle. The optical movement sensor is connected to the controller and provides vehicle movement signals thereto for use by the controller in computing vehicle position. The optical movement sensor can be either mounted on a gimbal for movement independent of the vehicle, or, alternatively, multiple optical movement sensors can be provided for detecting yaw movements. GNSS and inertial vehicle position tracking subsystems are also provided. Still further, a method of tracking a vehicle with an optical movement sensor is provided.