Patent classifications
G01S19/243
POSITION ESTIMATION FOR VEHICLES BASED ON VIRTUAL SENSOR RESPONSE
A method for determining an estimated position of a vehicle includes: receiving a measured sensor response determined with a scanning sensor of the vehicle, which is scanning an environment of the vehicle and determining the estimated position of the vehicle by generating a virtual sensor response for a possible position of the vehicle from an environmental map; and comparing the measured sensor response with the virtual sensor response for determining, how much the possible position and a real position of the vehicle at which the measured sensor response was generated, coincide.
GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS) MULTIPATH MITIGATION
A tracking loop and associated method for tracking a satellite signal in a GNSS receiver and for determining a line-of-sight (LOS) signal from a plurality of satellite signals received by the GNSS receiver from a satellite. One or more first correlators perform a correlation between a code signal derived from one of the received satellite signals and a plurality of corresponding replica code signals to determine a plurality of code correlation sums comprising a prompt code correlation sum, one or more early code correlation sums and one or more late code correlation sums. One or more second correlators correlate the plurality of code correlation sums with a plurality of replica carrier signals, each having a different Doppler frequency offset, to determine, for each of the plurality of code correlation sums, a set of correlation magnitudes at frequencies of the plurality of replica carrier signals. An LOS identification module identifies the LOS signal based on a signal propagation delay corresponding to one or more local maxima within the sets of correlation magnitudes.
TIME STAMPING ASYNCHRONOUS SENSOR MEASUREMENTS
A navigation receiver, a navigation system and a method of time stamping asynchronous sensor measurements is provided. Sensor measurement data is received at a first port. A signal pulse is received at a second port. The signal pulse represents a time of measurement according to a first time domain of the received sensor measurement data. Based on the received signal pulse, a timestamp according to a second time domain is generated. The generated timestamp is associated in the second time domain with the received sensor measurement data.
Multi-subband methods for reduced complexity, wideband blind resilient detection and geo-observable estimation of global navigation satellite signals
A method and apparatus is claimed here for reduced-complexity detection and estimation of geo-observables of global navigation satellite systems (GNSS) signals employing civil formats with repeating ranging codes, including true GNSS signals generated by satellite vehicles (SV's) or ground beacons (pseudo-lites), and malicious GNSS signals, e.g., spoofers and repeaters, using multi-subband symbol-rate synchronous channelization architectures that can exploit the full substantive bandwidth of the GNSS signals with managed complexity in each subband. Aspects employing spatial/polarization receivers are also claimed that can remove and geolocate non-GNSS jammers received by the system, as well as targeted GNSS spoofers that can otherwise emulate GNSS signals received at victim receivers. Aspects disclosed herein also provide time-to-first-fix (TTFF) over much smaller time intervals than existing GNSS methods; can operate in the presence of signals with much wider disparity in received power than existing techniques; and can operate in the presence of arbitrary multipath.
METHODS AND SYSTEMS FOR TRANSMITTING BASIC SAFETY MESSAGES
A method for broadcasting a basic safety message (BSM) packet from a host vehicle includes storing at least one path history entry of the host vehicle. The method includes determining whether a global navigation satellite system (GNSS) position fix is available. The method includes performing a corrective action on the at least one path history entry in response to the GNSS position fix not being available. The method includes, in response to the GNSS position fix being available, calculating a path history entry to be stored among the at least one path history entry based on the GNSS position fix. The method includes generating and broadcasting the BSM packet based on the at least one path history entry.
Detection and mitigation of satellite navigation spoofing
A device for mitigating satellite navigation spoofing includes processing circuitry which detects correlation peaks for PRNs in a satellite navigation signal. The TOAs of subframes of navigation messages associated with each of correlation peaks are recorded and analyzed to determine if they fall within a specified time window. Based on the analysis, the correlation peaks are classified as legitimate or as spoofed. A correct geographic location is computed from the navigation data associated with the legitimate correlation peaks. Corresponding methods for mitigating satellite navigation spoofing may be embodied in a hardware-based GNSS receiver and in a software-based GNSS receiver.
METHOD AND APPARATUS TO DETERMINE RELATIVE LOCATION USING GNSS CARRIER PHASE
Techniques are provided which may be implemented using various methods and/or apparatuses in a vehicle to determine proximate vehicles, for example, vehicles within a pre-designated range or within broadcast distance or otherwise geographically proximate, through the use of broadcast or other messages sent by the other vehicles, and to obtain GNSS carrier phase measurement data from the proximate vehicles wherein the shared carrier GNSS phase measurement data may be utilized to update the location(s) of proximate vehicles.
METHOD FOR DETECTING LOSS-OF-LOCK OF A GNSS SIGNAL TRACKING LOOP BASED ON FREQUENCY COMPENSATION
A method is for detecting loss-of-lock of a GNSS (Global Navigation Satellite System) signal tracking loop based on frequency compensation, comprising the following steps of: performing multi-channel frequency compensation on I-channel and Q-channel signals after down-conversion, pseudo-code stripping and integration clearing; then, performing coherent integration and non-coherent integration for a fixed time, and taking a maximum value of non-coherent integration results as a signal value; performing parabolic interpolation frequency identification, and taking an average value of the non-coherent integration results with the frequency differences of +/−50 Hz and +/−100 Hz as a noise value; and finally, calculating a ratio of the signal value to the noise value, and performing loss-of-lock detection with the ratio as a detection volume.
Self-assisted fast acquisition and first fix for a standalone GNSS receiver
A Global Navigation Satellite System (GNSS) positioning techniques is provided. A method to improve the time required to compute a position measurement in a GNSS receiver, and the time required to make this position measurement accurate is also provided. The method comprises computing a snapshot PVT (Position Velocity and Time) measurement, and use it to reduce the time required to acquire new signals to compute a conventional PVT measurement. A receiver implementing the method is further provided.
METHOD AND APPARATUS FOR PERFORMING JOINT CHANNEL AND TIME ESTIMATION IN A GNSS RECEIVER
A receiver is provided for use with a global navigation satellite system (GNSS) comprising multiple satellites. The receiver comprises a receiver clock and at least one antenna for receiving multiple signals over multiple respective channels, each channel being defined by a transmitting satellite and a receiving antenna at opposing ends of the channel. The receiver further comprises at least one correlator for calculating cross-correlation functions between (i) the signals received over the multiple channels and (ii) reference versions of the navigation signals provided by the receiver. The receiver is configured to use the calculated cross-correlation functions to perform a joint estimate of (i) a clock bias of the receiver clock relative to the time reference maintained by the GNSS, and (ii) a composite channel comprising the combined contribution of the multiple channels as a function of time-delay.