Method and apparatus for computing position and velocity of receiver using independently-derived sets of satellites

• US 7,280,071 B2
• Filed: 07/28/2005
• Issued: 10/09/2007
• Est. Priority Date: 07/30/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Awata, Hideki
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Chen; Shelley
• Application Number:
  US11/191,351
• Publication Number:
  US 20060022868A1
• Time in Patent Office: 803 Days
• Field of Search: 34235701-35715
• US Class Current: 342/357.35
• CPC Class Codes: G01S 19/28 Satellite selection
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A satellite-signal reception-processing apparatus for receiving signals, which each have completed a spectrum-spreading process using a spreading code, from a plurality of artificial satellites. Then, on the basis of the received signals, the apparatus computes its own position and velocity. The apparatus includes a position-computation satellite determination section for searching for a set of specific artificial satellites each having its locus known and the time of transmission of its spreading code also known, using this set to compute the position of the apparatus. The apparatus also includes a velocity-computation satellite determination section for searching for a set of particular artificial satellites each having its locus known and the frequency of its carrier determined to be a stable frequency, and using this set to compute the velocity of the apparatus.

Claims

1. A satellite-signal reception-processing apparatus for receiving signals, which each have completed a spectrum-spreading process using a spreading code, from a plurality of artificial satellites, and computing a position and velocity of said satellite-signal reception-processing apparatus on the basis of said received signals, said satellite-signal reception-processing apparatus comprising:

position-computation satellite determination means for carrying out an operation to search said artificial satellites for a set of specific artificial satellites each having its locus already known and a time of transmission of its spreading code also already known, a frequency of its carrier not being known as a stable frequency and designating said set found in said search operation as a set of position-computation artificial satellites to be used in computation of a position of said satellite-signal reception-processing apparatus; and

velocity-computation satellite determination means for carrying out an operation to search said artificial satellites for a set of particular artificial satellites each having its locus already known and a frequency of its carrier determined to be a stable frequency, a time of transmission of its spreading code not known and designating said set found in said search operation as a set of velocity-computation artificial satellites to be used in computation of a velocity of said satellite-signal reception-processing apparatus.

2. A satellite-signal reception-processing apparatus according to claim 1,

wherein said position-computation satellite determination means carries out an operation to search said artificial satellites each transmitting said signal, said spreading code and the frequency of said carrier of which have their synchronizations sustained, for said set of position-computation artificial satellites;

and

wherein said velocity-computation satellite determination means carries out an operation to search said artificial satellites each transmitting said signal, said spreading code and the frequency of said carrier of which have their synchronizations sustained, for said set of velocity-computation artificial satellites.

3. A satellite-signal reception-processing apparatus according to claim 1,

wherein a position of said satellite-signal reception-processing apparatus is computed only if a precision indicator determined by a layout of said position-computation artificial satellites is equal to or smaller than a position-precision indicator threshold value determined in advance;

and

wherein a velocity of said satellite-signal reception-processing apparatus is computed only if a precision indicator determined by a layout of said velocity-computation artificial satellites is equal to or smaller than a velocity-precision indicator threshold value determined in advance independently of said position-precision indicator threshold value.

4. A satellite-signal reception-processing apparatus according to claim 3,

wherein said velocity-precision indicator threshold value is a first DOP (Dilution Of Precision), and

wherein said position-precision indicator threshold value is a second DOP (Dilution Of Precision).

5. A satellite-signal reception-processing apparatus for receiving signals from a plurality of artificial satellites for computation of a position and velocity of said satellite-signal reception-processing apparatus as signals, which each have completed a spectrum-spreading process using a spreading code of said artificial satellite, and computing a position and velocity of said satellite-signal reception-processing apparatus on the basis of said received signals, said satellite-signal reception-processing apparatus comprising:

position-computation satellite determination means for searching said artificial satellites for a set of specific artificial satellites each transmitting said signal, said spreading code and the frequency of the carrier of which have their synchronizations sustained, searching said set of specific artificial satellites for final artificial satellites whose precision indicator determined by a layout of said artificial satellites used for computation of a position of said satellite-signal reception-processing apparatus is equal to or smaller than a position-precision indicator threshold value determined in advance and computing of a position of said satellite-signal reception-processing apparatus; and

velocity-computation satellite determination means for searching said artificial satellites for a set of particular artificial satellites each transmitting said signal, said spreading code and the frequency of the carrier of which have their synchronizations sustained, searching said set of particular artificial satellites for eventual artificial satellites whose precision indicator determined by a layout of said artificial satellites used for computation of a velocity of said satellite-signal reception-processing apparatus is equal to or smaller than a velocity-precision indicator threshold value determined in advance independently of said position-precision indicator threshold value and computing of a velocity of said satellite-signal reception-processing apparatus.

6. A satellite-signal reception-processing apparatus according to claim 5,

wherein said velocity-precision indicator threshold value is a first DOP (Dilution Of Precision), and

wherein said position-precision indicator threshold value is a second DOP (Dilution Of Precision).

7. A satellite-signal reception-processing method for receiving signals from a plurality of artificial satellites as signals, which each have completed a spectrum-spreading process using a spreading code of said artificial satellite, and computing a position and velocity of an apparatus adopting said satellite-signal reception-processing method on the basis of said received signals, said satellite-signal reception-processing method comprising the steps of:

determining a position-computation satellite for carrying out an operation to search said artificial satellites for a set of specific artificial satellites each having its locus already known and a time of transmission of its spreading code also already known, a frequency of its carrier not being known as a stable frequency and designating said set found in said search operation as a set of position-computation artificial satellites to be used in computation of a position of said apparatus adopting said satellite-signal reception-processing method;

determining velocity-computation satellite for carrying out an operation to search said artificial satellites for a set of particular artificial satellites each having its locus already known and a frequency of its carrier determined to be a stable frequency, a time of transmission of its spreading code not known and designating said set found in said search operation as a set of velocity-computation artificial satellites to be used in computation of a velocity of said apparatus adopting said satellite-signal reception-processing method; and

outputting the determined position and the determined velocity of the apparatus for further application.

8. A satellite-signal reception-processing method according to claim 7,

wherein said position-computation satellite determination process is carried out to search said artificial satellites each transmitting said signal, said spreading code and the frequency of said carrier of which have their synchronizations sustained, for said set of position-computation artificial satellites;

and

wherein said velocity-computation satellite determination process is carried out to search said artificial satellites each transmitting said signal, said spreading code and the frequency of said carrier of which have their synchronizations sustained, for said set of velocity-computation artificial satellites.

9. A satellite-signal reception-processing method according to claim 7,

wherein a position of said satellite-signal reception-processing apparatus is computed only if a precision indicator determined by a layout of said position-computation artificial satellites is equal to or smaller than a position-precision indicator threshold value determined in advance;

and

wherein a velocity of said satellite-signal reception-processing apparatus is computed only if a precision indicator determined by a layout of said velocity-computation artificial satellites is equal to or smaller than a velocity-precision indicator threshold value determined in advance independently of said position-precision indicator threshold value.

10. A satellite-signal reception-processing method according to claim 9,

wherein said velocity-precision indicator threshold value is a first DOP (Dilution Of Precision), and

wherein said position-precision indicator threshold value is a second DOP (Dilution of Precision).

11. An artificial-satellite signal reception method comprising the steps of:

computing a position of an apparatus adopting said artificial-satellite signal reception method by using signals received from a plurality of artificial satellites for which a position precision indicator is equal to or smaller than a position-precision indicator threshold value determined in advance where said position precision indicator is an indicator determined by a layout of artificial satellites used for computing a position of said apparatus;

computing a velocity of said apparatus by using signals received from a plurality of artificial satellites for which a velocity precision indicator is equal to or smaller than a velocity-precision indicator threshold value determined in advance independently of said position-precision indicator threshold value where said velocity precision indicator is an indicator determined by a layout of artificial satellites used for computing a velocity of said apparatus; and

outputting the determined position and the determined velocity of the apparatus for further application.

12. An artificial-satellite signal reception method according to claim 11,

wherein said velocity-precision indicator threshold value is a first DOP (Dilution Of Precision), and

wherein said position-precision indicator threshold value is a second DOP (Dilution of Precision).

13. A satellite-signal reception-processing apparatus for receiving signals from a plurality of artificial satellites as signals, which each have completed a spectrum-spreading process using a spreading code of said artificial satellite, and computing a position and velocity of said satellite-signal reception-processing apparatus on the basis of said received signals, said satellite-signal reception-processing apparatus comprising:

a position-computation satellite determination unit for carrying out an operation to search said artificial satellites for a set of specific artificial satellites each having its locus already known and a time of transmission of its spreading code also already known, a frequency of its carrier not being known as a stable frequency and designating said set found in said search operation as a set of position-computation artificial satellites to be used in computation of a position of said satellite-signal reception-processing apparatus; and

a velocity-computation satellite determination unit for carrying out an operation to search said artificial satellites for a set of particular artificial satellites each having its locus already known and a frequency of its carrier determined to be a stable frequency, a time of transmission of its spreading code not known and designating said set found in said search operation as a set of velocity-computation artificial satellites to be used in computation of a velocity of said satellite-signal reception-processing apparatus.