Lidar system incorporating multiple cameras for obtaining a plurality of subimages

• US 4,967,270 A
• Filed: 06/12/1989
• Issued: 10/30/1990
• Est. Priority Date: 05/08/1989
• Status: Expired due to Fees

• Current Assignee: Kaman Aerospace Corporation (Kaman Corporation)
• Original Assignee: Kaman Aerospace Corporation (Kaman Corporation)
• Inventors: Keeler, R. Norris, Ulich, Bobby L., Phlibsen, Kent
• Primary Examiner(s): Britton, Howard W.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US07/364,860
• Time in Patent Office: 505 Days
• Field of Search: 358/95, 358/83, 358/100, 358/99, 358/211, 358/113, 358/125, 358/110, 356/5, 356/6
• US Class Current: 348/31
• CPC Class Codes: G01S 17/18 wherein range gates are used
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04N 7/005 using at least one opto-electrical conversion device

Abstract

An improved imaging light detection and ranging (lidar) system is presented which provides variable time delay range gating across a selected image. Variable time delay range gating across an image is accomplished using a plurality of imaging cameras which are individually triggered after preselected delays to obtain multiple subimages. These multiple subimages are then put together in a mosaic in a computer to provide a complete image of a target plane using only one light pulse.

Claims

1. An apparatus for detecting and imaging an object enveloped by a backscattering medium which is at least partially transmitting to light comprising:

generating means for selectively generating short pulses of light;

projecting means for projecting said short pulses of light toward the backscattering medium and at an object enveloped by the medium;

detecting means for detecting said pulses of light reflected back from said object after a time delay corresponding to the round-trip propagation time of said light pulses to and from said object; and

converting means for converting said detected pulses of light to a video image of said object;

wherein said detecting means further comprises;

a plurality of cameras directed laterally across a target image, each of said cameras obtaining a subimage of said target image;

time delay generator means for selectively gating each of said cameras after a predetermined time delay to produce variable time delay gating across said target image viewed by said cameras.

2. The apparatus of claim 1 including:

means for combining all of the subimages from said cameras into a composite image.

3. The apparatus of claim 1 wherein:

said cameras are gated after one pulse from said generating means.

4. The apparatus of claim 1 wherein:

said target image is a planar image.

5. A method of detecting and imaging an object enveloped by a backscattering medium which is at least partially transmitting to light including the steps of:

selectively generating short pulses of light;

projecting said short pulses of light toward the backscattering medium and at an object enveloped by the medium;

detecting said pulses of light reflected back from said object after a time delay corresponding to the round-trip propagation time of said light pulses to and from said object;

converting said detected pulses of light to a video image of said object;

wherein said step of detecting said reflected pulses of light further includes using a detecting means comprising;

a plurality of cameras being directed laterally across a target image, each of said cameras obtaining a subimage of said target image; and

time delay generator means for selectively gating each of said cameras after a predetermined time delay to produce variable time delay gating across said target image viewed by said cameras.

6. The method of claim 5 including:

combining all of the subimages from said cameras into a composite image.

7. The method of claim 5 including:

gating said cameras after one pulse from said generating means.

8. The method of claim 5, wherein:

said target image is a planar image.

9. An apparatus for detecting and imaging an object enveloped by a backscattering medium which is at least partially transmitting to light comprising:

generating means for selectively generating short pulses of light;

projecting means for projecting said short pulses of light toward the backscattering medium and at an object enveloped by the medium;

detecting means for detecting said pulse of light reflected back from said object after a time delay corresponding to the round-trip propagation time of said light pulse to and from said object; and

converting means for converting said detected pulses of light to a vide image of said object;

wherein said detecting means further comprises;

a plurality of cameras;

time delay generator means for selectively gating each of said cameras after a predetermined time delay to produce variable time delay gating across an image viewed by said cameras;

wherein each of said cameras obtains a subimage; and

including

means for combining all of the subimages from said cameras into a composite image.

10. The apparatus of claim 9 wherein:

said target image is a planar image.

11. A method of detecting and imaging an object enveloped by a backscattering medium which is at least partially transmitting to light including the steps of:

selectively generating short pulses of light;

projecting said short pulses of light toward the backscattering medium and at an object enveloped by the medium;

detecting said pulses of light reflected back from said object after a time delay corresponding to the round-trip propagation time of said light pulses to and from said object;

converting said detected pulses of light to a video image of said object;

wherein said step of detecting said reflected pulses of light further includes using a detecting means comprising;

a plurality of cameras;

time delay generator means for selectively gating each of said cameras after a predetermined time delay to produce variable time delay gating across an image viewed by said cameras;

wherein each of said cameras obtains a subimage; and

including

combining all of the subimages from said cameras into a composite image.

12. The method of claim 11 wherein:

said target image is a planar image.