Embodiments of the present invention provide a method, system and computer program product for bit transition enhanced direct position estimation (DPE) from global navigation satellite system (GNSS) signals and includes the reception in a GNSS receiver of signals from multiple, different satellites in multiple satellite constellations adapted for use with the GNSS. The method estimates the GNSS receiver parameters position, velocity, clock bias, clock drift, and optionally and if unknown, the receiver time. The method generates a model of the received GNSS signals that depends on the receiver parameters. Uniquely, the method includes the synchronization of both a primary code and also a secondary code in the received GNSS signal model, in addition to time delays, Doppler shifts, and other relevant parameters for positioning. Finally, if the secondary code of a particular signal is unknown, the method determines the combination of bit transitions that maximizes the optimization problem.

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.

Certain implementations of the disclosed technology may include systems and methods for reducing noise in dual-frequency GNSS signal observation. The method can include: receiving, at a GNSS receiver, a first signal and a second signal. At least the second signal includes noise. The first signal is characterized by a first carrier frequency, and the second signal is characterized by a second carrier frequency. The method includes: down converting, sampling, cross-correlating, accumulating, determining ambiguous instantaneous phases, determining non-ambiguous instantaneous phases, producing normalized non-ambiguous instantaneous first phase samples, constructing a normalized first counter rotation phasor, generating a counter-rotated second observable, applying a low pass filter to remove noise; and outputting the filtered second observable.

A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM) and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The TRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system, receiver.

A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM) and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITTM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The ITRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system, receiver.

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.

An apparatus, a method, a method of manufacturing an apparatus, and a method of constructing an integrated circuit are provided. The apparatus includes a memory; and a processor configured to acquire K values with N peaks, where K and N are integers; select J of the N peaks and include the J peaks in track, where J is an integer less than or equal to N; determine a metric using acquisition non-coherent summations (NCSs) and track NCSs of coherent correlations; determine to not abandon the measurement based on the metric; and form a measurement responsive to determining to not abandon.

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.

Disclosed is a method and apparatus for correcting a satellite image acquisition time. The method may include receiving, from a ground-based orbit propagator, an initially predicted imaging time, a correction command execution time, and a desired satellite position for imaging, and calculating a waiting time for imaging, a predicted satellite position, a correction time, and a corrected imaging time to correct a satellite image acquisition time.

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.