Patent ID: 7889132
Filing Date: 2011-02-15
Classification: G01S

Abstract:
1. A method for identifying the location of an object by a TDOA (Time Difference of Arrival) principle comprising: transmitting a signal to a plurality of fixed stations having known positions by the object; transmitting a signal to each of the plurality of fixed stations by a fixed reference station having a known position relative to each of the plurality of fixed stations; generating an unknown transmission offset between the transmission of the signal from the object and the transmission of the signal from the reference station; determining a travel time difference between the arrival of the signal from the object and the arrival of the signal from the reference station for each of the plurality of fixed stations; determining a difference of the travel time differences between the plurality of fixed stations; and wherein a plurality of clocks corresponding to each of the plurality of fixed stations have different unknown time offsets relative to one another, and wherein location information is calculated by a mathematical method.