Patent ID: 6198694
Filing Date: 2001-03-06
Classification: F41J

Abstract:
A method for determining, without contact, at least one of a position, a direction, and a speed of a projectile in a flight path through a gas toward a target plane plane, said method comprising the steps of:arranging at least three acoustic sensors in a first plane, said first plane being located to intersect said flight path of said projectile toward said target plane;detecting, with each of said at least three acoustic sensors, acoustic sound waves generated by said projectile in said flight path toward said target plane through said gas;said acoustic sound waves detected with each of said three acoustic sensors emanating from at least one of:a turbulent gas volume extending substantially straight behind said projectile; anda wake or monopole extending substantially straight behind said projectile;determining time differences for arrival of said acoustic sound waves detected with each of said at least three acoustic sensors;calculating a position of said projectile in said first plane from said determined time differences; anddetermining a hit point of said projectile on said target plane from said calculated position of said projectile in said first plane.