Method of classifying and identifying an object using Doppler radar

• US 5,497,158 A
• Filed: 07/13/1994
• Issued: 03/05/1996
• Est. Priority Date: 07/15/1993
• Status: Expired due to Term

• Current Assignee: Deutsche Aerospace AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler-Benz Aerospace AG (Mercedes-Benz Group AG)
• Inventors: Schmitt, Peter, Schmid, Johannes
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/274,317
• Time in Patent Office: 601 Days
• Field of Search: 342/90, 342/25, 342/197, 342/190, 342/191
• US Class Current: 342/90
• CPC Class Codes: G01S 13/9027 Pattern recognition for feature extraction
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence

Abstract

The invention relates to a method of classifying and identifying an object, for example satellites, aircraft, land vehicles and ships with a Doppler radar system in which a video signal is generated by means of coherent signal processing and tracking data including, position and changes in position, are determined from the video signal for the object. The method includes representing the object as an inverse synthetic radar aperture image and then selecting a reference object with the aid of the tracking data and the rotational axis of the object. A representation of the reference object is rotated into a position that corresponds to the spatial rotational axis of the object and then superimposed over the inverse synthetic aperture radar image of the object. Identification of the object is effected by comparing the representation of the rotated reference object with the inverse synthetic aperture radar image.

Claims

1. A method of classifying and identifying an object with a Doppler radar system in which a video signal is generated by means of coherent signal processing, comprising:

determining at least position, change of position and spatial orientation of a rotational axis of the object from tracking data of the object;

representing the object as an inverse aperture synthetic radar image;

selecting a reference object with the aid of the tracking data and the determinations of said determining step;

rotating a representation of the reference object into a position that corresponds to the spatial orientation of the rotational axis of the object;

superimposing the representation of the rotated reference object over the inverse synthetic aperture radar image of the object; and

comparing the representation of the rotated reference object with the inverse synthetic aperture radar image to identify the object.

2. A method as defined in claim 1, wherein said representing step includes generating the inverse synthetic aperture radar image as a two-dimensional radar image.

3. A method as defined in claim 1, wherein said representing step includes producing the inverse synthetic aperture radar image with a pulse-modulated Doppler radar system.

4. A method as defined in claim 1, wherein said representing step includes producing the inverse synthetic aperture radar image with a mobile radar system.

5. A method as defined in claim 1, wherein said representing step includes producing the inverse synthetic aperture radar image with an onboard radar system of an aircraft.

6. A method as defined in claim 1, wherein the object is an aircraft.

7. A method as defined in claim 1, wherein the object is a ship.

8. A method as defined in claim 1, wherein the object is a land vehicle.

9. A method as defined in claim 1, wherein the object is an uncooperative participant in traffic.

10. A method of classifying and identifying a target aircraft with a Doppler radar system in which a video signal is generated by means of coherent signal processing, comprising:

determining a flight path, speed and spatial orientation of a rotational axis of the target aircraft from tracking data of the target aircraft;

representing the target aircraft as an inverse synthetic radar aperture image;

selecting a reference aircraft with the aid of the tracking data and the determinations of said determining step;

rotating a representation of the reference aircraft into a position that corresponds to the spatial orientation of the rotational axis of the target aircraft;

superimposing the representation of the rotated reference aircraft over the inverse synthetic aperture radar image of the target aircraft; and

comparing the representation of the rotated reference aircraft with the inverse synthetic aperture radar image to identify the target aircraft.