Patent ID: 6954404
Filing Date: 2005-10-11
Classification: G01S

Abstract:
1. A method for determining positions and velocities of targets from signals scattered by the targets, comprising the steps of: using a first station and a second station, each of said stations including a transmitter/receiver of electromagnetic or acoustic signals, and carrying out a mono-static measurement from each of said stations and also carrying out a bi-static measurement between said first and second stations as initial measurements; calculating, from said mono-static measurements, a number of target candidates with two-dimensional position and two-dimensional velocity; testing said target candidates against said bi-static measurement and retaining those target candidates that are found in all of said measurements with suitable error margins; said step of calculating taking place in a two-dimensional position space and a two-dimensional velocity space and giving the position and the velocity modulo rotational symmetry around a line through said first and second stations, use of said rotational symmetry enabling conceivable measured target positions in a three-dimensional space, which lies along arcs with a center on the axis of symmetry, to be represented by a point (P(t)) in a half-plane on one side of the axis of symmetry, making a two-dimensional position space, and said velocity being represented by a vector in a two-dimensional velocity space that is in a plane tangent to said point.