Patent ID: 8103294
Filing Date: 2012-01-24
Classification: G01S

Abstract:
1. A method of determining at a mobile terminal the elapsed time between two terminal positions and instants, the mobile terminal having a receiver for receiving the signals from plural transmission sources whose positions and transmission time offsets are unknown within the mobile terminal, the method comprising the steps of obtaining at a first position of the mobile terminal a first set of measurements, aligned to a first instant, of a signal parameter representative of the time or phase of receipt of said signals from said plural transmission sources relative to one of them, or to a reference, or to a mobile terminal clock; obtaining at a second position of the mobile terminal a corresponding second set of measurements, aligned to a second instant, of a signal parameter representative of the time or phase of receipt of said signals from said plural transmission sources relative to one or more of them, or to the said reference, another reference, or to the mobile terminal clock; and combining the aligned measurements of the first and second sets, and calculating at the terminal the elapsed time between the first and second instants from the combined aligned measurements of the first and second sets.