Abstract: The present invention is directed to a global positioning system (GPS) having improved signal-to-noise ratio for reducing the required signal level for which GPS may be implemented in electronic devices or cell phones. The acquisition function of the GPS receiver is improved by inserting new signal processing for broadband noise reduction that allows subsequent improved estimation of critical time shift and frequency shift parameters needed for GPS acquisition at lower received signal levels. The decoding of the navigation bits from the satellite transmissions is improved to provide ephemeris data needed for computing navigation solutions at lower received signal levels, by examining the output of the same new signal processing for broadband noise reduction for spikes in the power of the output time series that correspond to navigation bit flips.

Abstract: Methods including a Kalman filter tracking method for localizing a magnetic field source and which employs a linear perturbation method. The linear perturbation method linearizes an objective function in the neighborhood of the actual source enabling the source location to be computed in a single operation. Successive applications of the linear perturbation method lead to successive improvements in the localization result.

Abstract: A magnetic object tracking algorithm, that may be implemented as an apparatus or a method, that permits kinematic tracking of magnetized objects, or targets, using magnetic field strength measurements derived from one or more vector magnetometers. The magnetic object tracking algorithm effectively tracks a maneuvering magnetic dipole target using an extended Kalman filter directly observing (processing) real magnetic field strength data.