Acoustic optical scanning of linear detector array for laser radar

• US 5,870,181 A
• Filed: 10/28/1997
• Issued: 02/09/1999
• Est. Priority Date: 10/28/1997
• Status: Expired due to Term

• Current Assignee: Orbital ATK Inc. (Northrop Grumman Corporation)
• Original Assignee: Alliant Defense Electronics Systems, Inc. (Northrop Grumman Corporation)
• Inventors: Andressen, Clarence C.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/958,956
• Time in Patent Office: 469 Days
• Field of Search: 359/305, 356/141.1, 356/4.01
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/484 Transmitters

Abstract

A laser radar (LADAR) including an acoustic-optical (AO) laser scanner for deflecting a pulsed laser beam through a plurality of angles, means for diffracting the deflected laser beam from the acoustic-optical laser scanner into a plurality of laser beams and a linear detector array including a plurality of detector elements respectively positioned to receive reflected energy from the respective plurality of laser beams such that a line scan is produced composed of a plurality of pixels.

Claims

1. A scanner, comprising in combination:

an acoustic-optical laser scanner for deflecting a pulsed laser beam through a plurality of angles;

means for diffracting the deflected laser beam from the acoustic-optical laser scanner into a plurality of laser beams; and

a detector array including a plurality of detector elements respectively positioned to receive reflected energy from respective said plurality of laser beams,

whereby a line scan is produced composed of a plurality of pixels.

2. The scanner as set forth in claim 1, wherein said deflection of said pulsed laser beam through a plurality of angles by said acoustic-optical laser scanner comprises means for deflecting said pulsed laser beam at a different said angle for different said pulses of said laser beam.

3. The scanner as set forth in claim 2, wherein said deflecting of said pulsed laser beam at different said angles for different said pulses repetitively occurs until said deflection extends across a length of said detector elements to produce the line scan of closely positioned pixels.

4. The scanner as set forth in claim 3, further including a scan mirror for sequentially shifting said received reflected energy from respective said plurality of laser beams so as to produce sequential said line scans.

5. The scanner as set forth in claim 4, wherein alternate said detector elements are slightly offset to allow for continuous coverage and allow for the necessary separation between detectors to prevent shorting and cross coupling energy.

6. The scanner as set forth in claim 4, wherein multiple of said laser pulses are allowed to occur at the same said angle.

7. The scanner as set forth in claim 4, wherein said laser pulses do not occur at all of said angles.

8. A scanning method, comprising the steps of:

deflecting a pulsed laser beam through a plurality of angles;

diffracting the deflected laser beam into a plurality of laser beams;

receiving reflected energy from the respective plurality of laser beams and passing the reflective energy onto respective detector elements,

whereby a line scan is produced composed of a plurality of pixels.

9. The scanning method as set forth in claim 8, wherein the step of deflecting the pulsed laser beam through a plurality of angles comprises deflecting the pulsed laser beam at a different angle for different pulses of the laser beam.

10. The scanning method as set forth in claim 9, wherein the step of deflecting the pulsed laser beam at different angles for different pulses repetitively occurs until the deflection extends across a length of the detector elements to produce the line scan of closely positioned pixels.

11. The scanning method as set forth in claim 8, further including the step of sequentially shifting the received reflected energy from respective plurality of laser beams so as to produce sequential line scans.

12. The scanning method as set forth in claim 8, wherein a multiple of the laser pulses occurs at the same angle.

13. The scanning method as set forth in claim 8, wherein the laser pulses do not occur at all of the angles.