METHOD OF GEO LOCALIZATION OF A TERMINAL SENDING A SINGLE SIGNAL TO A SATELLITE SYSTEM

• US 20140145877A1
• Filed: 11/19/2013
• Published: 05/29/2014
• Est. Priority Date: 11/27/2012
• Status: Active Grant

• Current Assignee: Eutelsat, SA (Eutelsat Communications SA)
• Original Assignee: Eutelsat, SA (Eutelsat Communications SA)
• Inventors: Arcidiacono, Antonio, Finocchiaro, Daniele Vito, Le Pera, Alessandro
• Granted Patent: US 9,945,952 B2
• Time in Patent Office: Days
• US Class Current: 342/357.42
• CPC Class Codes: G01S 19/00 Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 5/011 Identifying the radio environment
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/0205 Details
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination

Abstract

A method for localizing a terminal includes transmitting the signal by the terminal; receiving the signal by a first and a second satellite; transmitting the signal from each satellite to a receiving station; demodulating the signal received by the first satellite to determine a signal content and the time of arrival of the signal transmitted by the terminal at the receiving station via the first satellite; determining the time of arrival of the signal transmitted by the terminal at the receiving station via the first and second satellite; determining a position for the terminal by triangulation.

Claims

1. A method for localizing a terminal adapted to send a signal to a first satellite, the method using at least a second satellite, the method comprising:

(a) transmitting the signal by the terminal;

(b) receiving the signal by the first and the second satellites;

(c) transmitting the signal from each of the first and second satellites to a receiving station;

(d) demodulating the signal received by the first satellite to determine a signal content and a time of arrival of the signal at the receiving station via the first satellite;

(e) determining the time of arrival of the signal at the receiving station via the second satellite by using the signal content and propagation properties determined using the demodulation of the signal received via the first satellite;

(f) determining a set of possible positions of the terminal by triangulation by using a difference of time of arrival of the signal to be received by the receiving station via the first and the second satellites.

2. The method according to claim 1, wherein the signal is a short duration signal.

3. The method according to claim 1, wherein the signal includes at least a terminal identifier.

4. The method according to claim 1, wherein the receiving station comprising:

a first receiving part to which the signal coming from the first satellite is transmitted, and

a second receiving part to which the signal coming from the second satellite is transmitted.

5. The method according to claim 1, wherein the receiving station comprises a processing unit that performs (d), (e), (f).

6. The method according to claim 1, further comprising calibrating to determine the precise positions of the satellites.

7. The method according to claim 1, wherein the signal content determined while demodulating the signal comprises:

data embedded in the signal;

a spreading code and/or emission parameters of the signal.

8. The method according to claim 1, further comprising detecting the signal received by the receiving station via the second satellite by using the signal content determined during the demodulating.

9. The method according to claim 1, wherein determining the time of arrival of the signal transmitted by the terminal at the receiving station via the second satellite by using the signal content comprises performing a correlation between a clean reconstructed copy of the demodulated signal received via the first satellite and the aggregate signal received via second satellite.

10. The method according to claim 1, further comprising:

receiving the signal by a third satellite,

determining the time of arrival of the signal transmitted by the terminal at the receiving station via the third satellite by using the signal content determined using the demodulation of the signal received by the first satellite;

determining the position of the terminal by triangulation by using the time of arrival of the signal transmitted by the terminal at the receiving station via the first, the second and the third satellites.

11. The method according to claim 1, wherein the signal is received via two different satellite or beams, the method further comprising:

computing the amplitude of the signal when received via the first satellite or beam;

computing the amplitude of the signal when received via the second satellite or beam;

determining the position of the terminal by triangulation, using;

the difference in time of arrivals of the signal transmitted by the terminal at the receiving station via the first and the second satellites;

the difference in amplitudes of the signal when received by the first and the second satellite or beam, knowing the coverage maps of the two satellites or beams.

12. A system to perform the method according to claim 1, the system comprising a receiving part and a processing unit.

13. A method for localizing a terminal adapted to send a signal to a first satellite, the method using at least a second satellite, the method comprising:

receiving the signal by the first and the second satellites from the terminal;

transmitting the signal from each of the first and second satellites to a receiving station;

demodulating the signal received by the first satellite to determine a signal content and a time of arrival of the signal at the receiving station via the first satellite;

determining the time of arrival of the signal at the receiving station via the second satellite by using the signal content and propagation properties determined using the demodulation of the signal received via the first satellite;

determining a set of possible positions of the terminal by triangulation by using a difference of time of arrival of the signal to be received by the receiving station via the first and the second satellites.