Abstract: A method of signal processing includes receiving samples of a signal and processing the samples using a time-windowed transform function to generate spectral data corresponding to each time window. The method includes generating first spectrogram data based on magnitudes of the spectral data and generating second spectrogram data based on phase differences of the spectral data. The method further includes combining the first spectrogram data and the second spectrogram data to generate a combined spectrogram and processing the combined spectrogram to generate output.

Abstract: A system and methods for dynamic routing under extreme cognitive jamming environments are presented. Jammer signals emitted by a network protocol-aware cognitive jammer are scanned for at a router node in an ad-hoc wireless network, and jammer behaviors are detected based on signal characteristics of the jammer signals. A network dynamic pattern caused by the network protocol-aware cognitive jammer is classified based on the detected jammer behaviors observed over a period of time, and dynamic routing strategies of the first router node are adapted to achieve robust data delivery based on the network behavioral pattern. Data packets sent by the router node are routed to avoid nodes and routes that are affected by the jammer signals.

Abstract: A system and methods for dynamic routing under extreme cognitive jamming environments are presented. Jammer signals emitted by a network protocol-aware cognitive jammer are scanned for at a router node in an ad-hoc wireless network, and jammer behaviors are detected based on signal characteristics of the jammer signals. A network dynamic pattern caused by the network protocol-aware cognitive jammer is classified based on the detected jammer behaviors observed over a period of time, and dynamic routing strategies of the first router node are adapted to achieve robust data delivery based on the network behavioral pattern. Data packets sent by the router node are routed to avoid nodes and routes that are affected by the jammer signals.

Abstract: A coherent processor having replica generator, a plurality of correlators, a combiner and a tracking loop. The replica generator generates a composite-reference signal having a replica of the plurality of the IM code, M code, P(Y) code or C/A code. The plurality of correlators correlates a received signal from a particular global positioning satellite, with the plurality of the IM code, M code, P(Y) code or C/A code, respectively, of the composite-reference signal, thereby generating a plurality of despread signals. The combiner combines the plurality of despread signals from the plurality of correlators. The tracking loop maintaines lock between the received signal and the composite-reference signal.

Abstract: Calibrating a receiver for a satellite positioning system. At preset intervals, a plurality of calibration signals are generated and applied to the receiver. The plurality of calibration signals correspond to a plurality of satellite signals, respectively, from the satellite positioning system. A relative time-delay bias from a delay estimation algorithm within the receiver. The time-delay bias is stored, preferably with the receiver. The receiver receives the plurality of satellite signals from the satellite positioning system. The plurality of satellite signals are processed with the time-delay bias. The processing reduces effects from the satellite receiver and improving estimate of the differential delay and total electron content (TEC).

Abstract: Calibrating a receiver for a satellite positioning system. At preset intervals, a plurality of calibration signals are generated and applied to the receiver. The plurality of calibration signals correspond to a plurality of satellite signals, respectively, from the satellite positioning system. A relative time-delay bias from a delay estimation algorithm within the receiver. The time-delay bias is stored, preferably with the receiver. The receiver receives the plurality of satellite signals from the satellite positioning system. The plurality of satellite signals are processed with the time-delay bias. The processing reduces effects from the satellite receiver and improving estimate of the differential delay and total electron content (TEC).