Velocity measuring system
AssigneeLarry C. Hardin
InventorsLarry C. Hardin, Lawrence V. Nash
Life of this patent
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Abstract
A passive electro-optical range and total velocity measuring system having first and second cameras positioned along a common baseline. Control systems activate the first and second cameras at a first instance to capture a target image of a target at location T1 and at a second instance to capture a target image of the target at location T2. A range computer calculates ranges from the first camera, the second camera, and a baseline midpoint to a target at location T1 and location T2. An angles computer calculates target displacement. A velocity computer calculates total total target velocity, track velocity, and cross-track velocity. The present invention also includes a method for measuring the range and total velocity of a target using a passive electro-optical system.
Claims4
A method for measuring the range and total velocity of a target using a passive electro-optical system oriented along a line of sight (LOS) axis, said system including first and second image acquisition devices positioned along a common baseline perpendicular to said LOS, said method comprising the steps of:
- (a) activating said first image acquisition device at a first instance t1 to capture a target image of a target at location T1 and at a second instance t2 to capture a target image of said target at location T2;
- (b) activating said second image acquisition device at said first instance t1 to capture a target image of said target at location T1 and at said second instance t2 to capture a target image of said target at location T2;
- (c) calculating ranges from said first image acquisition device to said target at location T1 and location T2;
- (d) calculating ranges from said second image acquisition device to said target at location T1 and location T2;
- (e) calculating a target displacement vector δR by performing the following steps:
- (i) defining a triangle A between said first image acquisition device, T1, and T2;
- (ii) defining a triangle B between said second image acquisition device, T1 and T2;
- (iii) solving triangle A to find δRA, a first approximate distance between T1 and T2;
- (iv) solving triangle B to find δRB, a second approximate distance between T1 and T2;
- and
- (v) averaging δRA and δRB to find a substantially accurate δR using the formula:
- δR=(δRA+δRB)/2);
- and
- (f) calculating total target velocity V.
Dependencies are inferred from the claim text.