초록 ▼

A method for estimating the location of the source of a (possibly unfriendly) electromagnetic probe signal (threat radar) received by an aircraft as the aircraft moves along a chosen path. A signal direction finder on the aircraft determines geometric parameters describing a probe signal plane that

A method for estimating the location of the source of a (possibly unfriendly) electromagnetic probe signal (threat radar) received by an aircraft as the aircraft moves along a chosen path. A signal direction finder on the aircraft determines geometric parameters describing a probe signal plane that contains a probe signal propagation direction, as received at the aircraft, at two or more selected times. A location determination system on the aircraft determines the location of the aircraft at each of the selected times. Information on the probe signal plane and the aircraft location is used to estimate initial location coordinates and, optionally, velocity coordinates and acceleration coordinates, for the probe signal source, in two dimensions or in three dimensions. Probe signal planes at additional selected times can be used to provide a check on, or provide a more reliable estimate for, the probe signal source location. The probe signal source may be transported on a land-based, water-based or airborne vehicle.

대표청구항 ▼

[ We claim:] [1.] A method for estimating the location of a source of probe signals of electromagnetic radiation received by an aircraft, the method comprising the steps of:receiving a probe signal at an aircraft at K distinct selected times (K.gtoreq.2), determining one or more selected parameters

[ We claim:] [1.] A method for estimating the location of a source of probe signals of electromagnetic radiation received by an aircraft, the method comprising the steps of:receiving a probe signal at an aircraft at K distinct selected times (K.gtoreq.2), determining one or more selected parameters that describe a probe signal surface that contains the probe signal propagation direction as the probe signal arrives at the aircraft, and determining the location coordinates of the aircraft, at each selected time;using the probe signal surface parameters and the aircraft location coordinates for the selected times to estimate the location of a source for the probe signal for at least one selected source location time;choosing said probe signal surface to be probe signal plane containing said probe signal propagation direction;choosing at least three of said selected parameters the describe the probe signal plane to be proportional to direction cosines of a line extending perpendicularly to the plane; andchoosing said selected number K to be at least 2; representing a first probe signal plane by a collection of two-dimensional Cartesian coordinates (x, y) that satisfy a first relation EQU (x-x.sub.a,i)cos(.phi..sub.a,i-.phi.PS,i)-(y-y.sub.a,i)sin(.phi..sub.a,i-.p hi.PS,i)=0(i=1);representing a second probe signal plane by a collection of two-dimensional Cartesian coordinates (x,y) that satisfy a second relation EQU (x-x.sub.a,i)cos(.phi..sub.a i-.phi.PS,i)-(y-y.sub.a,i)sin(.phi..sub.a,i-.phi.PS,i)=0(i=2); re (x.sub.a i,Y.sub.a,i) are the location coordinates of said aircraft at a time said probe signal plane parameters are determined (cos.phi..sub.a, i, sin.phi..sub.a, I) is a vector representing an orientation direction for said aircraft at a time said probe signal plane parameters are determined, and (cos.phi..sub.PS,i, sin.phi..sub.PS,i) is a vector representing said probe signal plane, for i=1,2;obtaining a simultaneous solution (x',y') for the location coordinates (x,y) that simultaneously satisfy the first and the second relations; andinterpreting the simultaneous solution (x',y') as two-dimensional location coordinates for said probe signal source.