Emitter location system

• US 7,176,831 B2
• Filed: 01/30/2003
• Issued: 02/13/2007
• Est. Priority Date: 02/15/2002
• Status: Expired due to Fees

• Current Assignee: Selex Communications Limited (Leonardo S.p.A.)
• Original Assignee: Selex Communications Limited (Leonardo S.p.A.)
• Inventors: Dibble, Anthony Sidney, Wyman, Glyn
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H.
• Application Number:
  US10/474,739
• Publication Number:
  US 20040233100A1
• Time in Patent Office: 1,475 Days
• Field of Search: 342/357.06, 342/357.01, 342450-452, 342/457, 342/465
• US Class Current: 342/357.48
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 2205/06 Emergency
• CPC Class Codes: G01S 5/0249 Determining position using measurements made by a non-stationary device other than the device whose position is being determined

Abstract

Described herein is a system and method for detecting the position of a remote emitter (1) where the emitter (1) is emitting a radio frequency signal (2) in a radio field (3). The system and method uses at least one receiver (4) which is moveable within the environment of the radio field (3), each receiver (4) measuring and recording the amplitude of the radio frequency signal (2) and recording its precise location using a GNSS or GPS receiver. The data recorded is processed and compared to data predicted by the receiver(s) (4) to estimate a location of remote emitter (1).

Claims

1. A system for locating an emitter emitting a radio frequency signal in a radio field, the system comprising:

a movable receiver capable of detecting and recording an amplitude of the radio frequency signal from a plurality of locations within radio field;

means for generating a grid of points representing an area of interest within the radio field;

means for calculating the distance between each of the grid points and the plurality of receiver locations;

means for calculating an expected signal strength for each of the grid points based on an assumed power and radiation efficiency of the emitter; and

means for generating a prediction of the location of the emitter.

2. A system for locating an emitter according to claim 1, further comprising additional moveable receivers each capable of detecting and recording the amplitude of the radio frequency signal from a plurality of locations.

3. A system for locating an emitter according to claim 1, further comprising a means for detecting the position of the receiver including a GNSS or GPS receiver.

4. A system for locating an emitter according to claim 1, wherein the receiver continuously detects and records the amplitude of the radio frequency signal whilst moving within the environment of the radio field.

5. A method of locating the position of an emitter emitting a radio frequency signal in a radio field, the method comprising the steps of:

(a) positioning a receiver in the radio field;

(b) recording the amplitude of the emitted signal at the receiver location;

(c) recording the receiver location;

(d) repositioning the receiver at a second location;

(e) recording the amplitude of the emitted signal at the second receiver location;

(f) recording the receiver location;

(g) generating a grid of points representing an area of interest within the radio field;

(h) calculating the distance between each of the grid points and the receiver locatios;

(i) calculating an expected signal strength for each of the grid points based on an assumed power and radiation efficiency of the emitter; and

(j) generating a prediction of the location of the emitter.

6. A method according to claim 5, further comprising the step of:

repeating steps (a) through (f) for a plurality of receiver locations.

7. A method according to claim 5, wherein steps (a) to (d) are carried out on two or more receivers.

8. A computer program product comprising program code means stored on a computer readable medium for performing the following method steps when the program is run on a computer and/or other processing means associated with suitable recording and locating devices;

(a) positioning a receiver in the radio field;

(b) recording the amplitude of the emitted signal at the receiver location;

(c) recording the receiver location;

(d) repeating steps (a) to (c) for a plurality of receiver locations in the radio field;

(e) generating a grid of points representing an area of interest within the radio field;

(f) calculating the distance between each of the grid points and receiver locations;

(g) calculating an expected signal strength for each of the grid points based on an assumed power and radiation efficiency of the emitter; and

(h) generating a prediction of the location of the emitter.