Visual recognition system for LADAR sensors

• US 5,644,386 A
• Filed: 01/11/1995
• Issued: 07/01/1997
• Est. Priority Date: 01/11/1995
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Loral Vought Systems Corporation (Martin Marietta Corporation)
• Inventors: Bornowski, Arthur Steven, Evans, Bruno Jack, Williams, David Collis Jr., Jenkins, Gary Kim
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/371,284
• Time in Patent Office: 902 Days
• Field of Search: 356/5.04, 356/4.01, 244/3.16, 382/224, 382/103, 348/143, 348/147, 348/384, 348/418, 250/342
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/48 of systems according to group G01S17/00
• CPC Class Codes: G01S 7/486 Receivers
• CPC Class Codes: G06V 20/64 Three-dimensional objects

Abstract

A visual recognition system is disclosed for detecting a target within a scene. A LADAR system and method is employed for scanning laser light signals across a scene having a target to be characterized. Laser light reflected from the target is detected and processed into a three-dimensional image. The three-dimensional image is segmented to separate the target from the overall scene. Substantially, only the segmented target data is either displayed locally or transmitted via a narrow bandwidth transmission medium to a remote site for display. The invention finds particular application in military situations where enemy armor is detected and the segmented version of the armor is transmitted via SINCGARS.

Claims

1. A method of detecting an object in a scene at a point remote from the scene, comprising the steps of:

laser scanning the scene to provide scan data representing a three-dimensional record of the scene including the object;

processing the scan data at a local site to segment the object in the scene; and

transmitting substantially only said segmented data to a remote site for viewing the object at the remote site.

2. The method of detecting according to claim 1 wherein the step of transmitting includes transmitting at a video rate over a transmission medium having a bandwidth of 16 kilobits per second or less.

3. The method according to claim 2 wherein the video transmission rate is on the order of 7.9 megabytes per second.

4. The method according to claim 1 and including the step of displaying the segmented data at the remote site in one of three optional modes.

5. The method according to claim 1 wherein the step of processing the scan data comprises the steps of:

a) detecting possible objects from the scan data;

b) segmenting the detected scan data to objects from the scene;

c) extracting features from the segmented data to distinguish between types of objects; and

d) classifying the segmented objects and extracted features according to known classifications.

6. The method according to claim 5 wherein the step of detecting includes the step of determining the existence of one or more surfaces of a particular shape relative to a ground plane.

7. The method according to claim 5 wherein the step of segmenting includes the steps of determining a dimension of the object relative to a ground plane, and projecting such objects onto a ground plane, so that the object can be separated from its background in the scene.

8. The method according to claim 5 wherein the step of extracting includes the step of determining a dimension of the object by measuring the distance between generally minimum and maximum extents of the object along an axis substantially parallel to an axis of that object.

9. A method of creating and transmitting an image of a target over a limited bandwidth transmission medium from an on-site location to a remote location, comprising the steps of:

LADAR scanning on-site a scene to provide scan data representing an on-site, three-dimensional record of the scene including the target;

processing the data on-site to separate segment data representative of the target from the remaining scene data;

transmitting substantially only the segment data to a remote site over the limited bandwidth transmission media; and

displaying the transmitted data at the remote site to provide an image of the target at the remote site.

10. The method of detecting according to claim 9 wherein the step of transmitting includes transmitting at a video rate over a transmission medium having a bandwidth of 16 kilobits per second or less.

11. The method according to claim 10 wherein the video transmission rate is on the order of 7.9 megabytes per second.

12. The method according to claim 10 wherein the step of displaying includes the step of displaying the target image in one of three optional modes.

13. Apparatus for displaying a target in a target scene, comprising:

a LADAR scanner for scanning the target scene to produce scan data representing a three-dimensional record of the scene including the target;

a data processor coupled to the LADAR scanner for correlating the scan data to identify a segment of the data representative of substantially only the target in relation to the scene and for producing segmented data representative of substantially only the target;

a transmitter coupled to the data processor for transmitting the segmented data to a site remote from the scene; and

a display operatively coupled to the transmitter for displaying the transmitted data at the remote site, thereby to display the target at the remote site.

14. The apparatus for displaying a target according to claim 13, and including a transmission medium linking the transmitter and the remote site, and having a bandwidth of 16 kilobits per second or less.

15. The apparatus for displaying according to claim 14 wherein the transmitter is a video transmitter for transmitting at video rates on the order of 7.9 megabytes per second.

16. The apparatus for displaying according to claim 14 wherein said display has means for visually presenting the target in one of three optional modes.

17. The apparatus for displaying a target according to claim 14 wherein the data processor includes:

a) means responsive to the scan data for detecting possible objects in the scene;

b) means responsive to the detected scan data for segmenting the object from the scene;

c) means for extracting features to distinguish between types of objects; and

d) means responsive to the segmented scan data and the extracted features for classifying the object according to known classifications.

18. The apparatus for displaying a target according to claim 17 wherein the means for segmenting includes means for determining a dimension of the object relative to a ground plane, and for projecting such objects onto a ground plane, so that the object can be separated from its background in the scene.

19. The apparatus for displaying a target according to claim 17 wherein the means for extracting includes means for determining a dimension of the object by measuring the distance between generally minimum and maximum extents of the object along an axis substantially parallel to an axis of that object.

20. The apparatus for displaying a target according to claim 17 wherein the means for detecting includes means for determining the existence of one or more surfaces of a particular shape relative to a ground plane.