US 7,126,877 B2Granted

System and method for disambiguating shooter locations

AssigneeBBN Technologies Corp.

InventorsJames Edwin Barger, Stephen Douglas Milligan, Marshall Seth Brinn, Richard J. Mullen

Life of this patent

Estimating the term…

Loading patent…

Abstract

Systems and methods for locating the shooter of supersonic projectiles based on shockwave-only measurements are described. Muzzle blast signals are neither sought nor required. The system uses at least five, preferably seven, acoustic sensors that are spaced apart at least 1 meter. The sensor signals are acquired with a time resolution in the order of microseconds and processed to find and disambiguate the shockwave arrival angle unit vector. Two different Time-Difference-Of-Arrival (TDOA) measurement techniques are described, with one technique using counters in each signal channel and the other technique using cross-correlation between signal channels. A genetic algorithm can be used to efficiently disambiguate the results.

Claims14

Dependent claims

A method for disambiguating a projectile trajectory from shockwave-only signals, comprising:

measuring at least an initial portion of the shockwave-only signals at five or more spaced acoustic sensors forming an antenna;
determining from the measured initial portion of the shockwave-only signals Time-Differences-Of-Arrival (TDOA) for sensor pairs;
applying a genetic algorithm to an initial chromosome, that comprises projectile trajectory assumptions, for a predefined number of generations;
computing residuals for solutions obtained with the chromosomes from the genetic algorithm;
performing a gradient search on a solution having a smallest residual and on its ambiguous alternate solution;
and
if a ratio of the solution having the smallest residual and its ambiguous alternate solution is greater than a predefined value, designating the solution having the smallest computed residual as the disambiguated projectile trajectory.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/925,875Filed 24 Aug 2004
Published: US 2006/0044943 A12 Mar 2006
Granted: 24 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

F41J 5/06
Target indicating systems; Target-hit or score detecting systems: acoustic hit-indicating systems, i.e. detecting of shock waves
G01S 3/808
Systems for determining direction or deviation from predetermined direction: using transducers spaced apart and measuring phase or time difference…
G01S 5/22
Using ultrasonic, sonic or infrasonic waves: position of source determined by co-ordinating a plurality of position lines defined by…
Y10S 367/906
Communications, electrical: acoustic wave systems and devices: airborne shock-wave detection