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Method of locating a transmitter

Patent image
NSA

A method of locating a transmitter is disclosed. A communications link is established between multiple receiving stations and a control station, and used with a calibration signal to calibrate out the time delay of the communications link. A radiated signal from an unknown transmitter is received at a receiving station and sent to the control station over the communications link. The time of arrival is recorded. Upon receiving a user input, the communication link switches from transmitting the received radiated signal to transmitting the calibration signal. The start of calibration signal is timed to begin at the same time across all of the receiving stations. The communication link time delay for each link is calculated by subtracting the start time from the received time, and the communication link time delay is subtracted from the received time recorded for the radiated signal. TDOA calculations are made to locate the transmitter.

Inventors: 
Kleinfelder, Walter J.; Meister, James E.
Patent Number: 
Technical domain: 
Sensors and Measurement
FIle Date: 
2008-03-04
Grant Date: 
2011-11-29
Grant time: 
1,365 days
Grant time percentile rank: 
25
Claim count percentile rank: 
8
Citations percentile rank: 
1
'Cited by' percentile rank: 
1
Assignee: 
NATIONAL SECURITY AGENCY