Abstract: A method of compensating for the temperature related frequency drift of an oscillator. The method comprises using an external reference frequency signal to derive oscillator compensation data over a range of operating temperatures, storing the oscillator compensation data in a first table, and, for a given operating temperature, using the first table to obtain corresponding oscillator compensation data and applying that data to provide compensation for the temperature related frequency drift. The method further comprises defining, for the range of operating temperatures, a series of temperature slots each sub-divided into a series of temperature bins.

Abstract: A method of compensating for the temperature related frequency drift of an oscillator. The method comprises using an external reference frequency signal to derive oscillator compensation data over a range of operating temperatures, storing the oscillator compensation data in a first table, and, for a given operating temperature, using the first table to obtain corresponding oscillator compensation data and applying that data to provide compensation for the temperature related frequency drift. The method further comprises defining, for the range of operating temperatures, a series of temperature slots each sub-divided into a series of temperature bins.

Abstract: This invention provides methods for a GPS device to resolve timing errors as applicable to a AGPS navigation solution, and, in particular, to solutions involving GNSS positioning and timing with limited assistance such as indoors or in a heavily obscured location, where the time of transmit of satellite signals is not directly extractable from the navigation message data. In particular the invention concerns the reconstruction of time-of-transmit from the course acquisition code of weak signals or where assisted-GNSS are employed.

Abstract: A method that is sub-optimal, but easily implemented, for cross correlation mitigation of GPS signals. It involves adaptive modification of the locally generated code used to detect a weak signal so that the new code is orthogonal to the jamming signals currently being tracked. The method employs simple constraints to achieve the orthogonalisation rather than a direct orthogonalisation performed using matrix inversions.

Abstract: The invention provides a GPS device that resolves timing errors as applicable to an AGPS navigation solution. A single state algorithm provides rapid convergence, typical with standard Newton-Raphson performance. Problems due to ill-conditioning of the input matrix are identified by an augmented DOP calculation procedure, which may be used to identify unreliable results or to estimate the errors for those results.

Abstract: A method, device and system for determining a receiver location using weak signal satellite transmissions. The invention involves a sequence of exchanges between an aiding source and a receiver that serve to provide aiding information to the receiver so that the receiver's location may be determined in the presence of weak satellite transmissions. With the aiding information, the novel receiver detects, acquires and tracks weak satellite signals and computes position solutions from calculated pseudo ranges despite the inability to extract time synchronization date f, 'n the weak satellite signals. The invention includes as features, methods and apparatus for the calibration of a local oscillator, the cancellation of cross correlations, a Doppler location scheme, an ensemble averaging scheme, the calculation of almanac aiding from a table of orbit coefficients, absolute time determination, and a modified search engine.