Abstract: A method of calculating two position fixes, using satellite positioning. The method comprises: using an RF front-end (12), receiving satellite positioning signals; using an analogue-to-digital converter (18), sampling the received signals to generate signal samples; using a processor (20), processing a first set of the samples as they are generated, to calculate a first position fix; storing information associated with the calculation in a memory (22); storing a second set of the samples, or ranging measurements derived from the second set of samples, in the memory (22) for later processing to calculate a second position fix; and later, processing the second set of samples to calculate the second position fix, wherein the calculation of the second position fix is assisted by the information associated with the calculation of the first position fix. Also disclosed are other related methods and apparatus.

Abstract: A method of calculating a position fix from satellite signal samples. The method comprises: obtaining first reference information produced during the calculation (120a) of a first position fix, the first position fix being the calculated position of a satellite-positioning receiver (5) at a first time; obtaining second reference information produced during the calculation (120b) of a second position fix, the second position fix being the calculated position of the receiver (5) at a second time; receiving a set of satellite signal samples generated by the receiver at a third time, or ranging measurements derived from such a set of satellite signal samples; and processing (140) the set of samples or the ranging measurements to calculate a third position fix. The processing (140) is assisted by the reference information produced during the calculation of the first and second position fixes.

Abstract: A method of calculating two position fixes, using satellite positioning. The method comprises: using an RF front-end (12), receiving satellite positioning signals; using an analogue-to-digital converter (18), sampling the received signals to generate signal samples; using a processor (20), processing a first set of the samples as they are generated, to calculate a first position fix; storing information associated with the calculation in a memory (22); storing a second set of the samples, or ranging measurements derived from the second set of samples, in the memory (22) for later processing to calculate a second position fix; and later, processing the second set of samples to calculate the second position fix, wherein the calculation of the second position fix is assisted by the information associated with the calculation of the first position fix. Also disclosed are other related methods and apparatus.