US 2002/0053987 A1 · Method and system for determining a position of an object using two-way ranging in a polystatic satellite configuration

Abstract

A method and system for determining a position of an object utilizes two-way ranging and polystatic techniques. A first communication transceiver at a first known location provides a bidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the first communication transceiver in response to the first ranging signal. The first communication transceiver further provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A second communication transceiver at a second known location provides a second unidirectional communication path between the second communication transceiver and the object wherein the second communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A signal processor determines a first path length corresponding to a first time length of the bidirectional communication path, a second path length corresponding to a second time length of the first and second unidirectional communication paths, and the position of the object based on the first and second known locations and the first and second path lengths.

Claims9

Dependent claims

A method for determining a position of an object, the method comprising:

transmitting a first ranging signal from a first satellite at a first known location to the object as directed by a satellite ground station;
transmitting a second ranging signal from the object to the first satellite in response to the first ranging signal for receipt by the satellite ground station;
transmitting a third ranging signal from a second satellite at a second known location to the object as directed by the satellite ground station;
transmitting a fourth ranging signal from the object to the first satellite in response to the third ranging signal for receipt by the satellite ground station;
transmitting a fifth ranging signal from a third satellite at a third known location to the object as directed by the satellite ground station;
transmitting a sixth ranging signal from the object to the first satellite in response to the fifth ranging signal for receipt by the satellite ground station;
determining a first delay corresponding to a time difference between transmission of the first ranging signal and receipt of the second ranging signal;
determining a second delay corresponding to a time difference between transmission of the third ranging signal and receipt of the fourth ranging signal;
determining a third delay corresponding to the time difference between transmission of the fifth ranging signal and receipt of the sixth ranging signal;
and
determining the position of the object based on the first, second, and third known locations and the first, second, and third delays.

8 more elements

A system for determining a position of an object, the system comprising:

a satellite ground station;
a first satellite at a first known location, wherein the first satellite transmits a first ranging signal to the object as directed by the satellite ground station and wherein the object transmits a second ranging signal to the first satellite in response to the first ranging signal for receipt by the satellite ground station;
a second satellite at a second known location, wherein the second satellite transmits a third ranging signal to the object as directed by the satellite ground station, wherein the object transmits a fourth ranging signal in response to the third ranging signal to the first satellite for receipt by the satellite ground station;
and
a third satellite at a third known location, wherein the third satellite transmits a fifth ranging signal to the object as directed by the satellite ground station, wherein the object transmits a sixth ranging signal to the first satellite in response to the fifth ranging signal for receipt by the satellite ground station;
wherein the satellite ground station determines a first delay corresponding to a time difference between transmission of the first ranging signal and receipt of the second ranging signal, a second delay corresponding to a time difference between transmission of the third ranging signal and receipt of the fourth ranging signal, and a third delay corresponding to a time difference between transmission of the fifth ranging signal and receipt of the sixth ranging signal, and determines the position of the object based on the first, second, and third known locations and the first, second, and third time delays.

3 more elements

Dependencies are inferred from the claim text.

Method and system for determining a position of an object using two-way ranging in a polystatic satellite configuration

Life of this patent

Method and system for determining a position of an object using two-way ranging in a polystatic satellite configuration

Life of this patent

Abstract

Claims9