Abstract: An observation lock detector block receives I&Q correlations and generates error measurement vectors, each including phase, frequency, code, pseudorange, and covariance residual estimates, and generates validity indicator and confidence indicator vectors, one of which error measurement vectors is an output as a selected error measurement vector with a respective validity indicator and confidence indicator vector, both of which selected vectors are communicated to a navigation solution processor in a ultratightly coupled navigation system for providing improved estimations of a navigation solution, the indicators indicating the usefulness of measurement errors, the prefilter detector block comprising discriminators, sequential filters, observation lock detectors and a measurement selector for selecting measurement vector based on phase, frequency, and code discriminations, the measurement errors being residual estimates that are indicated as valid or invalid for dynamic propagation of the residuals in a na

Abstract: An M code envelope detector receives an incoming binary offset carrier (BOC) signal, such as the M code signal, and generates inphase BOC and quadraphase BOC signals, separated by an offset, that have respective ambiguous correlation envelopes, that when combined, provide a near unimodal correlation function with respect to code phase error of the BOC signal having an inherent multimodal autocorrelation function, with the near unimodal correlation envelope being tracked by early and late code replicas at broad one chip phases for providing unambiguous but nonlinear code phase error tracking, which detector is then further improved with the use of code replicas having narrow partial chip phases, such as ? chip phases, for providing near linear code phase error tracking for unambiguous and accurate code tracking of the BOC signal.

Abstract: An observation lock detector block receives I&Q correlations and generates error measurement vectors, each including phase, frequency, code, pseudorange, and covariance residual estimates, and generates validity indicator and confidence indicator vectors, one of which error measurement vectors is an output as a selected error measurement vector with a respective validity indicator and confidence indicator vector, both of which selected vectors are communicated to a navigation solution processor in a ultratightly coupled navigation system for providing improved estimations of a navigation solution, the indicators indicating the usefulness of measurement errors, the prefilter detector block comprising discriminators, sequential filters, observation lock detectors and a measurement selector for selecting measurement vector based on phase, frequency, and code discriminations, the measurement errors being residual estimates that are indicated as valid or invalid for dynamic propagation of the residuals in a na

Abstract: A multitarget tracking antispoofing receiver utilizes multitarget tracking algorithms and multiple correlators for tracking signals of interest in a field of view about a nominal trajectory of a desired true signal for tracking targets within the code phase and carrier frequency signal space so as to predict when true and spoof signals will cross paths in the signal space without spoofing with loss of tracking of the desired signal so that true tracking of a desired target is maintained in the presence of a spoofing signal moving along a spoofing signal track and crossing a true path of the true signal.

Abstract: A direct sequence spread spectrum receiver includes a first spreading code generator for receiving a first channel signal spectrum spread by a first spread code, while a second group of receivers use a second spreading code, where the first and second codes are partially correlated, so that, the first group of receivers receive all messages communicated while the second group of receivers only receives a portion of the messages. In this manner, a spread spectrum broadcast system can selectively communicate to a selected portion of receivers in a whole group of receivers by simply switching the spreading code at the transmitter.

Abstract: A direct sequence spread spectrum receiver includes a first spreading code generator for receiving a first channel signal spectrum spread by a first spread code, while a second group of receivers use a second spreading code, where the first and second codes are partially correlated, so that, the first group of receivers receive all messages communicated while the second group of receivers only receives a portion of the messages. In this manner, a spread spectrum broadcast system can selectively communicate to a selected portion of receivers in a whole group of receivers by simply switching the spreading code at the transmitter.

Abstract: An ultratight coupling method generates navigation error state information from an integration Kalman filter for updating the navigation solution based upon inertial measurement data and computes pseudorange and pseudorange rate data from the navigation solution and from ephemeris data, to generate the prompt, early and late replica signals that drive the signal correlators having quadrature outputs samples by a federation of Kalman prefilters providing errors residuals to the integration Kalman filter in a closed coupled tracking loop. The coupled tracking loops offer improved tracking of the received signal based upon updated navigation solution.