Method and system for determining the position of an object

• US 7,187,327 B2
• Filed: 04/01/2004
• Issued: 03/06/2007
• Est. Priority Date: 04/01/2004
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Coluzzi, Michael Eugene, Kang, Sung Phill
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H
• Application Number:
  US10/814,649
• Publication Number:
  US 20060250305A1
• Time in Patent Office: 1,069 Days
• Field of Search: 342/458, 342/387, 342463-465
• US Class Current: 342/458
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/781 Secondary Surveillance Radar [SSR] in general
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

A method and system for determining the location of an object. The system may implement a number of sensors at different locations that are positioned to receive a transmitted or reflected signal from the object. Also disclosed is a system and method of calculating object position based upon the time difference of arrival (TDOA) from each sensor, or the relative time difference of arrival (RTDOA). A known distribution of noise is added to the time of arrival (TOA) prior to calculating the object position.

Claims

1. A method for determining the position of an object in a system comprising a sensor arranged at a determinable location, the method comprising:

obtaining a time of arrival for a signal received at the sensor

calculating a slant range from the object to the sensor based, at least in part, upon the obtained time of arrival;

wherein calculating the slant range further comprises;

adding a known distribution of noise to the time of arrival;

prior to calculating the slant range; and

determining a position vector based, at least in part, upon the calculated slant range and the location of the sensor.

2. The method of claim 1 wherein the time of arrival is obtained from a signal transmitted from the object.

3. The method of claim 1 wherein the time of arrival is obtained from a signal reflected from the object.

4. The method of claim 1 wherein the known distribution of noise comprises a Gaussian noise distribution with a variance of σ

².

5. The method of claim 1 wherein determining a position vector further comprises:

calculating an error norm for each possible position vector solution; and

selecting as the object position vector the position vector solution with the smallest error norm.