METHOD FOR CLOCK CALIBRATION IN A POSITION DETERMINATION SYSTEM

摘要

Timing signals are transmitted from reference transmitters through antenna/receivers (antenna preamplifier nodes) to collector nodes (C-Nodes) and to a central computer. The times of arrival of the signals at the various C-Nodes are measured by the C-Nodes, relative to each C-Node's clock. The time of arrival signals at each CNode must be based upon a common time reference to be useful for positioning. Therefore, the central computer determines the offsets ofclocks relative to a selected reference C-Node clock. The time of arrival signals are then calibrated against one another and used to adjust the time of arrival signals so that all time-of-arrivals are relative to the same reference and can be used for position determination and the clocks of the collection nodes are effectively synchronized.