Two-stage target tracking system and method

• US 5,214,433 A
• Filed: 06/17/1992
• Issued: 05/25/1993
• Est. Priority Date: 06/17/1992
• Status: Expired due to Fees

• Current Assignee: Southeastern Center for Electrical Engineering Education, The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Alouani, Ali B. T., Rice, Theodore R., Blair, William D.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US07/899,803
• Time in Patent Office: 342 Days
• Field of Search: 342/96, 342/67, 342/96, 342/195, 342/196, 342/101
• US Class Current: 342/95
• CPC Class Codes: G01S 13/723 by using numerical data

Abstract

An apparatus and method for tracking maneuvering and non-maneuvering targ in the presence of stochastic acceleration are provided. The apparatus and method utilize a two-stage Kalman estimator, the first stage of which is a bias-free filter providing target position and velocity estimates, and the second stage of which is a bias filter providing estimates of target acceleration. These two filters act together to provide parallel processing calculations thereby achieving high speed target state determination. During target maneuvers, the output of the second stage is used to correct the output of the first stage. In the absence of maneuver, the second stage is turned off and the first stage provides the target position and velocity estimates.

Claims

1. A target tracking system for maneuvering and non-maneuvering targets comprising:

a target tracking sensor;

a two-stage Kalman estimator receiving target position and velocity from said target tracking sensor and estimating corrected target velocity and acceleration using a bias-free filter stage for providing target position and velocity estimates and a decoupled, bias filter for providing target acceleration estimates; and

a target display system connected to and receiving corrected target data from said two-stage Kalman estimator.

2. A target tracking system as in claim 1 wherein said target tracking sensor comprises a radar transmitter and receiver.

3. A target tracking system as in claim 1 wherein said target tracking sensor comprises an electro-optic tracker.

4. A target tracking system for maneuvering and non-maneuvering target comprising:

means for sensing target positions and velocity;

means for correcting target position information functionally connected to and receiving signals from said means for sensing, said means for correcting further comprising means for parallel processing of acceleration data along with simultaneous and decoupled processing of estimated velocity and position data; and

means for displaying corrected target position information as received for said means for correcting.

5. A method for estimating target position and tracking a maneuvering target comprising the steps of:

emitting energy for target detection;

receiving target position and velocity signals;

reading received signals simultaneously into a constant velocity Kalman filter and into a separate target acceleration Kalman filter;

providing the output of the constant velocity Kalman filter as a first estimate of target position and velocity;

detecting target acceleration by measuring the magnitude of residuals for the constant velocity filter alone;

summing constant velocity and acceleration filter outputs whenever the constant velocity residuals exceed a pre-set value;

estimating target position and velocity data using the greater of the constant velocity filter outputs or the sum of the constant velocity an acceleration filter outputs; and

displaying corrected target position and velocity data.