Method for improving the target position vector accuracy of an amti radar

Claim 1

In conjunction with an observer aircraft equipped with an AMTI radar system capable of providing target range and course interferometer bearing data, the method of deriving a target position vector of improved accuracy comprising the steps of assigning values for the parameters of minimum range, bearing at minimum range, target velocity, and time at which the target is at minimum range for the true target path, analytically extending a course target velocity vector obtained from the radar system output to a minimum range condition, taking a series of target position measurements at times t1, t2, . . . tn, calculating on the basis of the extended range, bearing and velocity values at minimum range condition the target position at time tn, deriving an error function from the difference between the final measured target position values and the calculated target position values, minimizing said error functions for range bearing and velocity values at the minimum range condition, adjusting the extended range, bearing and velocity values for minimum range conditions to incorporate said minimized error functions, and calculating a target position vector from said adjusting values.