Method of determining the position of a target using transmitters of opportunity

• US 20050057395A1
• Filed: 06/27/2002
• Published: 03/17/2005
• Est. Priority Date: 08/03/2001
• Status: Active Grant

• Current Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Original Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Inventors: Atkinson, Simon John, Weedon, Robert John, Baker, Adam Alexander, Rickett, Bryan Stephen, Smith, Christopher Nigel
• Granted Patent: US 7,155,240 B2
• Time in Patent Office: Days
• US Class Current: 342/464
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 19/00 Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems

Abstract

A method of determining the position of a target comprising the steps of: providing a transmitter or a plurality of transmitters to transmit a signal to the target, providing a receiver or a plurality of receivers to receive signals reflected from said target. Determining the time of arrival information of said reflected signal at the or each receiver; using information pertaining to the position of the or each receiver and/or the or each transmitter and with the information obtained determining the target position. Preferably the signal includes a modulated or coded portion unique to the transmitter; and said signal portion is associated with the or each particular transmitter by virtue of said signal portion. The signal maybe a mobile phone transmission, DAB, digital TV, digital Radio or digital satellite transmissions.

Claims

1. In a communication system wherein pre-stored codes are used in transmissions as part of the communication protocol, a method of determining the position of a target comprising the steps of:

a) providing a transmitter or to transmit a signal to the target,

b) providing a plurality of receivers, in communication with each other, to receive signals reflected from said target, the receivers being time or phase synchronised;

c) determining the time of arrival information of said code of reflected signal at each receiver by continuously correlating said received signal with the prestored codes in the receiver;

d) using information pertaining to the position of each receiver and with the information obtained from step c), determining the target position.

3. A method as claimed in claim 1 wherein transmitted signals includes a modulated or coded portion unique to the transmitter which is used to identify the transmitter and hence its location for step (e).

4. A method as claimed in claim 1, wherein all the receivers communicate said time of arrival information and receiver identification to central unit.

5. A method as claimed in claim 4 wherein said central unit is one of the receivers.

6. A communication system having a plurality of transmitters and a plurality of receivers, using combined information obtained via the methods of claim 1 to determine the location of a target.

7. A method as claimed in claim 1, wherein said signal is a mobile phone transmission, DAB, digital TV, digital Radio or digital satellite transmission.

8. A method as claimed in claim 1, wherein said signal includes the mid-amble or a portion thereof or any unique sequence of data that is known to the receiver before transmission.

2. In a communication system wherein pre-stored codes are used in transmissions as part of the communication protocol, a method of determining the position of a target comprising the steps of:

a) providing a plurality of transmitters to transmit each a signal to the target, said transmitters being time or phase synchronized;

b) providing a receiver to receive signals reflected from said target and wherein said signals are set out pre-set times known to the receiver;

c) correlating said received signal with the pre-stored codes in each receiver to identify the transmitter of a particular signal;

d) the receiver determining the time delay in receiving said signal by subtracting the time of arrival of a pre-stored code of each reflected signal from each transmitter from the known time the pre-stored code was sent,

e) using information known to the receiver pertaining to the position of each transmitter and with the timing information obtained from step c), determining the target position.