Method and system for recognizing targets at long ranges

• US 5,408,541 A
• Filed: 01/05/1993
• Issued: 04/18/1995
• Est. Priority Date: 01/05/1993
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Sewell, Kenneth G.
• Primary Examiner(s): Mancuso, Joseph
• Application Number:
  US08/000,601
• Time in Patent Office: 833 Days
• Field of Search: 382/1, 382/48, 356/3, 356/7, 356/12, 356/4, 248/143, 248/144, 248/148
• US Class Current: 382/291
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/486 Receivers
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes

Abstract

An improved method and system (30) for recognizing targets (16) at long-ranges permits target recognition at or near the ranges at which the targets are initially detected. The method includes the steps of detecting (32) the target (16) relative to a sensor platform (12), and, in response to the detection, determining a set of range parameters (40) from the sensor platform (12) to the target (16). After transferring the set of range parameters to a gated television sensor (44) that serves as an imaging device, the method next involves illuminating the target area associated with the range parameters with a laser pulse (42) to generate reflected energy (48) from the target (16). The reflected energy (48) is then highly magnified and imaged (46) using the gated television sensor (44). The image (46) may be sent to an automatic target recognizor system (70) or displayed for operator recognition (72).

Claims

1. An improved method for recognizing a target, comprising the steps of:

(a) detecting a target relative to a sensor platform;

(b) determining a set of range and angle parameters from said sensor platform to the target;

(c) transferring said set of range and angle parameters to an imaging recognition sensor associated with said sensor platform, said imaging recognition sensor comprising a laser source and a gated television sensor;

(d) illuminating the target according to said set of range and angle parameters with an imaging laser pulse from said laser source, the target reflects at least some of the energy of the imaging laser pulse generating reflected energy from the target;

(e) collecting and highly magnifying a portion of said reflected energy;

(f) imaging said highly-magnified portion using said gated television sensor to generate a plurality of target images; and

(g) recognizing the target from at least one of said plurality of target images as the target.

2. The method of claim 1, wherein said detecting step comprises the step of detecting a thermal image of the target.

3. The method of claim 1, wherein said detecting step comprises the step of detecting a radar signal return from the target.

4. The method of claim 1, wherein said detecting step further comprises the step of generating a set of coordinates relating to the target, and wherein said determining step further comprises the step of illuminating with a measurement laser pulse an area associated with said set of coordinates.

5. The method of claim 1, wherein said imaging step further comprises the step of gating said gated television sensor as a function of said set of range and angle parameters to reduce backscatter from said imaging laser pulse prior to said illuminating the target step.

6. The method of claim 1, wherein said determining step further comprises the step of directing to the target a measurement laser pulse having a lower pulse energy than said imaging laser pulse.

7. The method of claim 6, wherein said determining step further comprises the step of directing said measurement laser pulse as a pulse having an energy equivalent to said imaging laser pulse.

8. The method of claim 1, wherein said recognizing step further comprises the step of recognizing the target using an automatic target classifier.

9. The method of claim 1, further comprising the step of enhancing for display said plurality of target images.

10. An improved method for recognizing a target, comprising the steps of:

detecting a target relative to a sensor platform;

generating a set of range and angle parameters from said sensor platform to the target in response to said detecting step;

passing said set of range and angle parameters to an imaging recognition sensor, said imaging recognition sensor comprising a laser-aided imaging recognition sensor (LAIRS) system, said LAIRS system comprising a laser source for generating an imaging laser pulse and a gated television sensor, said gated television sensor operating at the same wavelength as said imaging laser;

illuminating the target according to said range and angle parameters with the imaging laser pulse from said laser source, the target reflects at least some of the energy of the imaging laser pulse generating reflected energy from the target;

collecting and highly magnifying a portion of said reflected energy;

imaging said highly-magnified portion using said gated television sensor to generate a plurality of target images; and

recognizing the target from at least one of said plurality of target images.

11. The method of claim 10, further comprising the step of aiming said LAIRS system at the target as a function of said set of coordinates.

12. The method of claim 10, wherein said illuminating step further comprises illuminating the target according to said set of coordinates with an imaging laser pulse with a beam width larger than the target.

13. The method of claim 10, wherein said imaging step further comprises imaging said highly-magnified portion using said gated television to minimize backscatter from intervening atmosphere between the target and said sensor platform and to remove range diverse backgrounds at other than the coordinates of the target.

14. The method of claim 10, wherein said generating step further comprises the step of directing to the target a measurement laser pulse have a lower pulse energy than said imaging laser pulse.

15. A method for increasing the recognition range of a target, comprising the steps of:

detecting a target relative to a sensor platform;

generating angle coordinates associated with the target;

providing said angle coordinates to a laser-aided imaging recognition sensor (LAIRS) system, said LAIRS system comprising a laser illuminator and an imaging device operating at the same wavelengths as said laser illuminator;

aiming said LAIRS system in accordance with said angle coordinates;

illuminating the target with a measurement laser pulse for measuring a range from said LAIRS system to the target and determining from said range a set of gating parameters associated with said imaging device;

illuminating the target with an imaging laser pulse, the target reflects at least a portion of the energy of the imaging laser pulse generating reflected energy from said target;

gating said imaging device in accordance with said gating parameters to receive said energy reflected from the target;

collecting and highly magnifying a portion of said reflected energy;

imaging said energy reflected from the target on the imaging device to form an image of the target; and

recognizing said image of the target.

16. The method of claim 15, wherein said detecting step comprises the step of detecting a radar return from the target.

17. The method of claim 15, wherein said detecting step comprises the step of detecting infrared emissions from the target.

18. The method of claim 15, further comprising the step of enhancing said image of the target for display.

19. The method of claim 15, further comprising the step of recognizing said image of the target using an automatic target recognizer.