A method and apparatus detects and estimates geo-observables of navigation signals employing civil formats with repeating baseband signal components, i.e., “pilot signals,” including true GNSS signals generated by satellite vehicles (SV's) or ground beacons (pseudolites), and malicious GNSS signals, e.g., spoofers and repeaters. Multi-subband symbol-rate synchronous channelization can exploit the full substantive bandwidth of the GNSS signals with managed complexity in each subband. Spatial/polarization receivers can be provided to remove interference and geolocate non-GNSS jamming sources, as well as targeted GNSS spoofers that emulate GNSS signals. This can 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.

A GNSS receiver to track low power GNSS satellite signals. The GNSS receiver includes a frequency locked loop (FLL) that measures a current doppler frequency of the satellite signal. A delay locked loop (DLL) measures a current code phase delay of the satellite signal. A current operating point corresponds to the current doppler frequency and the current code phase delay of the satellite signal. A grid monitor receives the satellite signal and the current operating point, and measures a satellite signal strength at a plurality of predefined offset points from the current operating point. The FLL and the DLL are centered at the current operating point. A peak detector is coupled to the grid monitor and processes the satellite signal strengths at the plurality of predefined offset points and re-centers the FLL and the DLL to a predefined offset point with the satellite signal strength above a predefined threshold.

The present invention discloses a joint non-coherent integral vector tracking method based on a spatial domain, which is used for further improving the performance of a vector tracking GPS (Global Positioning System) receiver. In a new vector tracking strategy design, a phase discriminator/a frequency discriminator in a traditional vector tracking loop is discarded, and baseband signals of visible satellites in each channel are taken as an observation value after performing non-coherent integration, and EKE (abbreviation of Extended Kalman Filter) is used to estimate directly and to solve the position, the velocity, a clock error, etc. of the GPS receiver. Because of the existence of non-coherent integral calculation, when GPS satellite signals are relatively weak, a carrier to noise ratio of an observation value may be effectively improved, and the tracking sensitivity is improved.

A method, apparatus, computer program, and data structure relating to: causing correlation of a digital signal provided by a receiver with a motion-compensated correlation code, wherein the motion-compensated correlation code is a correlation code that has been compensated before correlation using one or more phasors dependent upon an assumed or measured movement of the receiver.

The present invention relates to a system and method using hybrid spectral compression and cross correlation signal processing of signals of opportunity, which may include Global Navigation Satellite System (GNSS) as well as other wideband energy emissions in GNSS obstructed environments. Combining spectral compression with spread spectrum cross correlation provides unique advantages for positioning and navigation applications including carrier phase observable ambiguity resolution and direct, long-code spread spectrum signal acquisition. Alternatively, the present invention also provides unique advantages for establishing the validity of navigation signals in order to counter the possibilities of electronic attack using spoofing and/or denial methods.

An approach to joint processing of GNSS signals to determine a receiver location and common mode bias associated with grouped records corresponding to GNSS signals. In this regard, a receiver may acquire signals from a GNSS space vehicle over a relatively long period of time. In turn, records corresponding to received signals may be stored and grouped. The grouping of records may be based on assumptions of a common-mode bias for certain records (e.g., records acquired within a given duration of an observation time period). Upon acquisition of a suitable number of records, an over-determined system may be established that is used in iterative processing to solve for location and/or bias values associated with the respective common-mode bias for each group of records. As such, improved receiver performance may be realized.

In an embodiment, a method is provided. The method comprises selecting at least one set of line of sight (LOS) vectors oriented in one or more directions outward from a vehicle; determining at least one air data solution based on the at least one set of LOS vectors; adjusting at least one value of an air vector equation based on a predetermined quantity; upon adjusting the at least one value, then determining at least one modified air data solution, wherein the at least one modified air data solution is determined based on the at least one set of LOS vectors and the at least one value; and comparing a difference between the at least one air data solution and the at least one modified air data solution to a threshold value, wherein the threshold value is indicative of error with respect to the at least one set of LOS vectors.

A method, apparatus, computer program, data structure, signal relating to: causing correlation of a digital signal provided by a receiver with a motion-compensated correlation code, wherein the motion-compensated correlation code is a correlation code that has been compensated before correlation using one or more phasors dependent upon an assumed or measured movement of the receiver.

A global navigation satellite system (GNSS) receiver includes: at least one radio frequency (RF) front end configured to receive a GNSS signal from a single GNSS antenna and to digitize the GNSS signal into a digitized GNSS signal; at least one processor configured to: calculate weight to be applied to a sample of a block of samples of the digitized GNSS signal; apply the weight to at least one sample of the block of samples of the digitized GNSS signal to create a weighted GNSS signal; and perform signal processing on the weighted GNSS signal.

A positioning receiver includes a processor configured to process a GNSS satellite transmitted navigation message received from at least one respective satellite vehicle to provide a navigation message data packet and to determine for each data bit of the navigation message data packet a respective confidence value; and to determine positioning data based on the data bits of the navigation message data packet and respective confidence values.