Method for determining the position of an object, a positioning system, a receiver and an electronic device

• US 6,433,733 B2
• Filed: 05/08/2001
• Issued: 08/13/2002
• Est. Priority Date: 05/08/2000
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Kontola, Ilkka, Syrjarinne, Paula
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Mull, Fred H.
• Application Number:
  US09/851,239
• Publication Number:
  US 20010045905A1
• Time in Patent Office: 462 Days
• Field of Search: 342/357.08, 342/357.09, 342/357.1
• US Class Current: 342/357.31
• CPC Class Codes: G01S 19/51 Relative positioning
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Abstract

The invention relates to a method for determining the position of an object to be searched for. The method applies a receiver (RX1) for the object to be searched substantially in the vicinity of the object to be searched, a receiver (RX2) for a searcher, with respect to which the position of the object to be searched is determined, and satellites (SV1-SV4) from which a code-modulated random spectrum signal is transmitted, and positioning data of the satellites are determined. In the method, a default position (└{circumflex over (x)}_S,ŷ_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘) is determined for the receiver (RX2) of the searcher; pseudo ranges (ρ_i1) to at least three satellites (SV1-SV4) are measured on the basis of signals received from the satellites in the receiver (RX1) of the object to be searched; pseudo ranges (ρ_i2) to at least said three satellites (SV1-SV4) are measured on the basis of signals received from the satellites in the receiver (RX2) of the searcher; and at least the direction and distance (└Δx,Δy,Δz,Δt┘) of the object to be searched from the receiver (RX2) of the searcher are determined.

Claims

1. A method for determining the position of an object to be searched, which method applies a receiver (RX1) for an object to be searched, substantially in the vicinity of the object to be searched, a receiver (RX2) for a searcher, with respect to which the position of the object to be searched is determined, and satellites (SV1-SV4) from which a code-modulated random spectrum signal is transmitted;

and determining positioning data of the satellites, characterized in that in the method, at least the following steps are performed;

determining a default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) for the receiver (RX2) of the searcher,

measuring pseudo ranges (ρ

_i1) to at least three satellites (SV1-SV4) on the basis of signals received from the satellites, in the receiver (RX1) of the object to be searched,

measuring pseudo ranges (ρ

_i2) to at least said three satellites (SV1-SV4) on the basis of signals received from the satellites, in the receiver (RX2) of the searcher, and

determining at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher, wherein said determining step employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver.

2. The method according to claim 1, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be search determined in the receiver (RX2) of the searcher, wherein information on the measured pseudo ranges is transmitted from the receiver (RX1) of the object to be searched to the receiver (RX2) of the searcher.

3. The method according to claim 1, characterized in that the method applies a communication network, wherein a data transmission link is formed from the receiver (RX1) to be searched and from the receiver (RX2) of the searcher to said communication network, at least for the transmission of said information on pseudo ranges.

4. The method according to claim 1, characterized in that the method also comprises at least the following steps:

determining the geometrical distance (r_i) from the receiver (RX2) of the searcher to said at least three satellites (SV1-SV4) on the basis of the positioning data and said default position,

correcting the pseudo ranges (ε

_i) measured in the receiver (RX1) of the object to be searched and in the receiver (RX2) of the searcher on the basis of the determined geometrical distance, and

using the corrected pseudo ranges for determining the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher.

5. The method according to claim 1, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched are determined by determining the position of the receiver of the object to be searched and by calculating the difference between the default position of the receiver (RX2) of the searcher and the position of the receiver (RX1) of the object to be searched.

6. The method according to claim 1, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched are determined by Taylor'"'"'s method of linearization.

7. The method according to claim 6, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched are determined by solving the set of equations;

${\mathrm{\rho <br><br>}}_{\mathrm{iL}}={\mathrm{\rho <br><br>}}_{\mathrm{iS}}-\frac{x_i-x_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>x-\frac{y_i-y_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>y-\frac{z_i-z_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>z+c<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>t,i=1,\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},n<br><br>\text{\hspace{1em}<br><br>}$

in which

n=the number of satellites (SV1-SV4) used for positioning,

c=the speed of light └

x_S,x_S,z_S┘

=the position of the receiver (RX2) of the searcher,

└

x_i,y_i,z_i┘

=the position of satellites at moment of transmission of the signal used in the calculation of the pseudo ranges, and

Δ

t=the clock error.

8. The method according to claim 1, characterized in that the pseudo ranges are measured by the following formulas:

9. A positioning system comprising a receiver (RX1) for an object to be searched, substantially located in the vicinity of the object to be searched;

a receiver (RX2) for a searcher, in relation to which the position of the object to be searched is arranged to be determined; and

satellites (SV1-SV4) comprising means for transmitting a code-modulated random spectrum signal and means for determining positioning data of the satellites;

characterized in that the positioning system also comprises at least;

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher,

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i1) between the receiver (RX1) to be searched and at least three satellites (SV1-SV4) on the basis of signals received from the satellites,

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i2) between the receiver (RX2) of the searcher and said at least three satellites (SV1-SV4) on the basis of signals received from the satellites, and

means (5) for determining the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher, wherein said determining means employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver.

10. The positioning system according to claim 9, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched is arranged to be determined in the receiver (RX2) of the searcher, wherein the positioning system also comprises means (9, NW) for transmitting information on the measured pseudo ranges from the receiver (RX1) to be searched to the other receiver (RX2).

11. The positioning system according to claim 9, characterized in that the positioning system also comprises a communication network (9, NW) and means (9, BS) for forming a data transmission link from the receiver (RX1) to be searched and from the receiver (RX2) of the searcher to said communication network, at least for transmitting said information on the pseudo ranges.

12. The positioning system according to claim 9, characterized in that it also comprises:

means (5) for determining the geometrical distance (r_i) between the receiver (RX2) of the searcher and said at least three satellites (SV1-SV4) on the basis of the positioning data and said default position,

means (5) for correcting (ε

_i) the pseudo ranges measured in the receiver (RX1) of the object to be searched and in the receiver (RX2) of the searcher on the basis of the determined geometrical distance, and

means (9, BS) for using the corrected pseudo ranges in determining the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher.

13. The positioning system according to claim 9, characterized in that the means (5) for determining the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher comprise means (9, BS) for determining the position of the receiver of the object to be searched and means (5) for calculating the difference between the default position of the receiver (RX2) of the searcher and the position of the receiver (RX1) of the object to be searched.

14. The positioning system according to claim 9, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher is arranged to be determined by Taylor'"'"'s method of linearization.

15. The positioning system according to claim 14, characterized in that the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher is arranged to be determined by solving the set of equations;

$\begin{array}{cc}{\mathrm{\rho <br><br>}}_{\mathrm{iL}}={\mathrm{\rho <br><br>}}_{\mathrm{iS}}-\frac{x_i-x_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>x-\frac{y_i-y_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>y-\frac{z_i-z_S}{{\mathrm{\rho <br><br>}}_{\mathrm{iS}}}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>z+c<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>t,<br><br>i=1,\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},n<br><br>\text{\hspace{1em}<br><br>}& \left(9\right)\end{array}$

in which

n=the number of satellites (SV1-SV4) used for positioning,

c=the speed of light

└

x_S,x_S,z_S┘

=the position of the receiver (RX2) of the searcher,

└

x_i,y_i,z_i┘

=the position of satellites at moment of transmission of the signal used in the calculation of the pseudo ranges, and

Δ

t=the clock error.

16. The positioning system according to claim 9, characterized in that the pseudo ranges are arranged to be measured by the following formulas:

17. A receiver (RX2) for a searcher, comprising means (CH1-CH4) for receiving code-modulated random spectrum signals transmitted by satellites (SV1-SV4), and means (CH1-CH4, 9) for determining positioning date of satellites, characterized in that the receiver (RX2) also comprises at least:

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher,

means (CH1-CH4,2) for receiving pseudo ranges (ρ

_i1) transmitted by a receiver (RX1) for an object to be searched, located substantially in the vicinity of the object to be searched, measured from the receiver (RX1) to be searched on the basis of signals received from at least three satellites (SV1-SV4),

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i2) from the receiver (RX2) to said at least three satellites (SV1-SV4) on the basis of signals received from the satellites, and

means (5) for determining at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher, wherein said determining means employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver.

18. A receiver (RX2) for a searcher, which is arranged to be used in a positioning system comprising a receiver (RX1) for an object to be searched, placed substantially in the vicinity of the object to be searched for, satellites (SV1-SV4) comprising means for transmitting a code-modulated random spectrum signal, and means (CH1-CH4, 9) for determining positioning data of the satellites, and which receiver (RX2) comprises means for receiving the code-modulated random spectrum signals transmitted by the satellites (SV1-SV4), characterized in that the receiver (RX2) of the searcher also comprises at least:

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i2) from the receiver (RX2) of the searcher to said at least three satellites (SV1-SV4) on the basis of signals received from the satellites, and

means (CH1-CH4, 2) for transmitting said measured pseudo ranges (ρ

_i2) to the positioning system, and

means (CH1-CH4, 2) for receiving data on at least the direction and distance (└

Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the positioning system,

wherein the positioning system also comprises;

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher,

means (BS) for receiving the pseudo ranges (ρ

_i1) transmitted by the receiver (RX1) of the object to be searched, placed substantially in the vicinity of the object to be searched, the pseudo ranges (ρ

_i1) being measured between the receiver (RX1) to be searched and at least three satellites (SV1-SV4) on the basis of signals received from the satellites,

means (BS) for receiving said pseudo ranges (ρ

_i2) measured in the receiver of the searcher,

means (5) for determining at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher, wherein said determining means employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver, and

means (BS) for transmitting data on at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched to the receiver (RX2) of the searcher.

19. An electronic device comprising a receiver (RX2) for a searcher, means (CH1-CH4) for receiving code-modulated random spectrum signals transmitted by satellites (SV1-SV4), and means (CH1-CH4, 9) for determining positioning data of the satellites, characterized in that the electronic device also comprises at least:

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher,

means (CH1-CH4, 2) for receiving pseudo ranges (ρ

_i1) transmitted by a receiver (RX1) for an object to be searched, placed substantially in the vicinity of the object to be searched, the pseudo ranges (ρ

_i1) being measured between the receiver (RX1) to be searched and at least three satellites (SV1-SV4) on the basis of signals received from the satellites,

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i2) between the receiver (RX2) of the searcher and said at least three satellites (SV1-SV4) on the basis of signals received from the satellites, and

means (5) for determining at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) between the object to be searched and the receiver (RX2) of the searcher, wherein said determining means employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver.

20. The electronic device according to claim 19, characterized in that it also comprises means (8, 9, 10, 11, 12a, 12b, 12c) for performing functions of a mobile station.

21. An electronic device which is arranged to be used in a positioning system comprising a receiver (RX1) for an object to be searched, placed substantially in the vicinity of the object to be searched, satellites (SV1-SV4) which comprise means for transmitting a code-modulated random spectrum signal and means (CH1-CH4, 9) for determining positioning data of the satellites, and which electronic device comprises a receiver (RX2) for a searched and means (CH1-CH4) for receiving code-modulated random spectrum signals transmitted by satellites (SV1-SV4), characterized in that the electronic device also comprises at least:

means (CH1-CH4, 2) for measuring pseudo ranges (ρ

_i2) between receiver (RX2) of the searcher and said at least three satellites (SV1-SV4) on the basis of signals received from the satellites, and

means (CH1-CH4, 2) for transmitting said measured pseudo ranges (ρ

_i2) to the positioning system, and

means (CH1-CH4, 2) for receiving data on at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the positioning system,

wherein the positioning system also comprises;

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher,

means (BS) for receiving the pseudo ranges (ρ

_i1) transmitted by the receiver (RX1) of the object to be searched, placed substantially in the vicinity of the object to be searched, the pseudo ranges (ρ

_i1) being measured between the receiver (RX1) of the object to be searched and at least three satellites (SV1-SV4) on the basis of signals received from the satellites,

means (BS) for receiving the said pseudo ranges (ρ

_i2) measured in the receiver of the searcher,

means (5) for determining at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched from the receiver (RX2) of the searcher, wherein said determining means employs the pseudo ranges measured by the object receiver and the pseudo ranges measured by the searcher receiver based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver, and

means (BS) for transmitting data on at least the direction and distance (└

Δ

x,Δ

y,Δ

z,Δ

t┘

) of the object to be searched to the receiver (RX2) of the searcher.

22. The electronic device according to claim 21, characterized in that it also comprises means (8, 9, 10, 11, 12a, 12b, 12c) for performing functions of a mobile station.

23. A computing server which is arranged to be used in a positioning system comprising a receiver (RX1) for an object to be searched, placed substantially in the vicinity of the object to be searched, satellites (SV1-SV4) which comprise means for transmitting a code-modulated random spectrum signal and means (CH1-CH4, 9) for determining positioning data of the satellites, and which system further comprises a receiver (RX2) for a searcher and means (CH1-CH4) for receiving code-modulated random spectrum signals transmitted by the satellites (SV1-SV4), characterized in that the server also comprises at least:

means (BS) for receiving pseudo ranges (ρ

_i1) transmitted by the receiver (RX1) of the object to be searched, placed substantially in the vicinity of the object to be searched, the pseudo ranges (ρ

_i1) being measured between the receiver (RX1) of the object to be searched and at at least three_satellites (SV1-SV4) on the basis of signals received from the satellites,

means (BS) for receiving said pseudo ranges (ρ

_i2) measured in the receiver of the searcher, the pseudo ranges (ρ

_i2) being measured between the receiver (RX1) of the searcher and the at least three satellites (SV1-SV4) on the basis of signals received from the satellites,

means (5) for determining at least the direction and distance (└

Δ

_x,Δ

_y,Δ

_z,Δ

_t┘

) of the object to be searched from the receiver (RX2) of the searcher, and

means (BS) for transmitting data on at least the direction and distance (└

Δ

_x,Δ

_y,Δ

_z,Δ

_t┘

) of the object to be searched to the receiver (RX2) of the searcher,

wherein the positioning system also comprises;

means (BS) for determining the default position (└

{circumflex over (x)}_S,ŷ

_S,{circumflex over (z)}_S,{circumflex over (t)}_S┘

) of the receiver (RX2) of the searcher, wherein determination by the positioning system are based on an assumption that there is a common error in measurements performed by the object receiver and by the searcher receiver.