Abstract: A system and method for detection of GNSS signal spoofing with high integrity error bounding determines a parity space formulation for coordinates of a GNSS-driven master position solution (e.g., fully absolute/GNSS or blended GNSS/IRS solution) and a corresponding coasted position solution (e.g., less frequently GNSS-updated), wherein a parity vector expresses consistency of the master coordinate with the coasted coordinate. Based on a desired level of missed detection, protection levels are determined for the parity space formulation, and integrity bounds on the master and coasted solutions calculated. The parity vector is compared with a detection threshold. If, for any solution component (e.g., direction, axis) of the master solution, the parity vector meets or exceeds the threshold, a spoofer is detected and a coasted solution is propagated with its coasted integrity bound. If no spoofer is detected, the master solution and its master integrity bound are propagated as output.

Abstract: A receiver device to receive an incoming radio frequency (RF) satellite signal from a satellite vehicle includes a processor and computer-readable storage media. The computer-readable storage media is communicably connected to the processor and has instructions stored thereon that, when executed by the processor, causes the processor to track the incoming RF satellite signal in code phase and carrier frequency, the incoming RF satellite signal having a primary pseudorandom (PRN) code and a secondary PRN code modulated thereon, generate an encoded sequence of dot product values of adjacent integrated in-phase (I) and quadrature-phase (Q) components of the incoming RF satellite signal, compare the encoded sequence with expected secondary code chip transitions, determine a secondary code phase for the secondary PRN code based on the comparison, and coherently integrate the secondary code phase with the incoming RF satellite signal to increase an integration interval.

Abstract: A system and for determining precision navigation solutions decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms. The set of decorrelated floating-point ambiguities is used to compute protection levels and the probability of almost fix (PAF), or the probability that the partial almost-fix solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities. While the PAF remains below threshold and the protection levels remain below alert levels, the optimal navigation solution (floating-point, partial almost-fix, or fully fixed) is generated by fixing the decorrelated ambiguities are one at a time in the LAMBDA domain and replacing the appropriate carrier-phase ambiguities with the corresponding fixed ambiguities, reverting to the last solution if PAF reaches the threshold or if protection levels reach the alert levels.

Abstract: Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

Abstract: A system and for determining precision navigation solutions decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms. The set of decorrelated floating-point ambiguities is used to compute protection levels and the probability of almost fix (PAF), or the probability that the partial almost-fix solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities. While the PAF remains below threshold and the protection levels remain below alert levels, the optimal navigation solution (floating-point, partial almost-fix, or fully fixed) is generated by fixing the decorrelated ambiguities are one at a time in the LAMBDA domain and replacing the appropriate carrier-phase ambiguities with the corresponding fixed ambiguities, reverting to the last solution if PAF reaches the threshold or if protection levels reach the alert levels.

Abstract: A system and related method for determining precision navigation solutions is disclosed. The system decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms. The set of decorrelated floating-point ambiguities is used to compute protection levels and the probability of almost fix (PAF), or the probability that the partial almost-fix solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities.

Abstract: A receiver device to receive an incoming radio frequency (RF) satellite signal from a satellite vehicle includes a processor and computer-readable storage media. The computer-readable storage media is communicably connected to the processor and has instructions stored thereon that, when executed by the processor, causes the processor to track the incoming RF satellite signal in code phase and carrier frequency, the incoming RF satellite signal having a primary pseudorandom (PRN) code and a secondary PRN code modulated thereon, generate an encoded sequence of dot product values of adjacent integrated in-phase (I) and quadrature-phase (Q) components of the incoming RF satellite signal, compare the encoded sequence with expected secondary code chip transitions, determine a secondary code phase for the secondary PRN code based on the comparison, and coherently integrate the secondary code phase with the incoming RF satellite signal to increase an integration interval.

Abstract: A receiver device to receive an incoming radio frequency (RF) satellite signal from a satellite vehicle includes a processor and computer-readable storage media. The computer-readable storage media is communicably connected to the processor and has instructions stored thereon that, when executed by the processor, causes the processor to track the incoming RF satellite signal in code phase and carrier frequency, the incoming RF satellite signal having a primary pseudorandom (PRN) code and a secondary PRN code modulated thereon, generate an encoded sequence of dot product values of adjacent integrated in-phase (I) and quadrature-phase (Q) components of the incoming RF satellite signal, compare the encoded sequence with expected secondary code chip transitions, determine a secondary code phase for the secondary PRN code based on the comparison, and coherently integrate the secondary code phase with the incoming RF satellite signal to increase an integration interval.

Abstract: Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

Abstract: A receiver device to receive an incoming radio frequency (RF) satellite signal from a satellite vehicle includes a processor and computer-readable storage media. The computer-readable storage media is communicably connected to the processor and has instructions stored thereon that, when executed by the processor, causes the processor to track the incoming RF satellite signal in code phase and carrier frequency, the incoming RF satellite signal having a primary pseudorandom (PRN) code and a secondary PRN code modulated thereon, generate an encoded sequence of dot product values of adjacent integrated in-phase (I) and quadrature-phase (Q) components of the incoming RF satellite signal, compare the encoded sequence with expected secondary code chip transitions, determine a secondary code phase for the secondary PRN code based on the comparison, and coherently integrate the secondary code phase with the incoming RF satellite signal to increase an integration interval.

Abstract: A system and related methods for determining precision navigation solutions decorrelates GPS carrier-phase ambiguities derived from multiple-source GPS information via Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) algorithms, and fixes a subset of the decorrelated integer ambiguities within the LAMBDA domain. To maintain high accuracy, a partial almost fix solution is generated using the subset of the decorrelated ambiguities to be fixed in the LAMBDA domain. The subset of decorrelated ambiguities is used to compute protection levels and the probability of almost fix (PAF), or that the navigation solution corresponding to the decorrelated ambiguities is within the region of correctly-fixed or low-error almost-fixed ambiguities. The partial list of fixed ambiguities is used to generate the optimal navigation solution (floating-point, partial almost-fix, or fully fixed) while maintaining protection levels within alert limits and PAF above the desired threshold.