Direction finding method and system using probabilistic mapping

• US 7,408,509 B2
• Filed: 02/24/2004
• Issued: 08/05/2008
• Est. Priority Date: 02/24/2003
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Karlsson, Lars, Soloviev, Dmitri
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H.
• Application Number:
  US10/785,356
• Publication Number:
  US 20040164902A1
• Time in Patent Office: 1,624 Days
• Field of Search: 342/449, 342450-452, 342/457, 342/465
• US Class Current: 342/449
• CPC Class Codes: G01S 3/046 Displays or indicators
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders

Abstract

A Direction Finding Method and System Using Probabilistic Mapping is disclosed. Also disclosed is a preferred system that employs a technique for taking in data sets (lines of bearing) from DF receivers and characterizing those signals with their respective probabilities of error. Then using a unique method, the preferred system can display the triangulated position on a map with an overlay of probability fields indicating the emitter location with varying levels of confidence. Even further, the preferred system is able to redraw the probability fields on the map display in real-time as new data is collected and updated. In this way, a far more efficient EL System has been achieved in which the emitter'"'"'s position can be determined more quickly. It should be noted that with this invention, triangulation can be done with just a single (mobile) DF Set in the EL System. Today'"'"'s systems for triangulation must use at least three DF Sets.

Claims

1. A direction-finding method comprising the steps of:

establishing a cross-over position point, said cross-over point defined as the intersection between LOBs generated by at least two receiving incident electronic signal;

relocating one said receiver to a new receiver spacial location;

said receiver at said new receiver position receiving a transmission from a transmitter at a transmitter position;

determining a real-time line of bearing from said receiver at said new receiver position to said transmitter;

generating a connecting vector from said real-time line of bearing to said cross-over position point; and

identifying a real-time position of said transmitter along said connecting vector;

displaying said real-time position on a user display panel; and

generating and displaying probability overlay map responsive to said real-time position and said quality factor on said user display panel.

2. The method of claim 1, wherein said identifying step further comprises assigning a probability factor to said real-time position of said transmitter responsive to said quality factor and said probability overlay map generating and displaying is responsive to said probability factor.

3. The method of claim 2, further comprising a repeating step to repeat said relocating, receiving, determining, generating, identifying, displaying and generating steps until said probability factor exceeds a predetermined threshold value.

4. The method of claim 2, further comprising a repeating step to repeat said relocating, receiving, determining, generating, identifying, displaying and generating steps until said probability factor meets a user-defined threshold value.

5. The method of claim 2, further comprising a repeating step to repeat said relocating, receiving, determining, generating, identifying, displaying and generating steps until a user terminates said direction finding method.