Linear mode computational sensing LADAR

Patent metadata

Field	Value
Publication number	US-9823350-B2
Application number	US-201414448465-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Jul 31, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

Laser light pulsed to illuminate and reflect from at least one object is received at a digital micro-mirror device including an array of mirrors each of which may be selectively controlled to be oriented to either reflect incident light onto a detector or not. The detector outputs a signal representative of an amount of light sensed. By applying M spatial patterns to the mirrors, each in synchronization with one pulse from the laser, and storing sampled signal values from the detector output at each of K times following a pulse from the laser, the collected information may be used to reconstruct K images each using all M spatial patterns and stored sampled signal values corresponding to a respective one of the K times. Each of the K images corresponds to a different range to the digital micro-mirror device, such that the system may be employed as a range finder.

First claim

What is claimed is:

1. An apparatus, comprising:
a laser configured to pulse laser light illuminating at least one object;
a digital micro-mirror device oriented to receive laser light reflected from the at least one object and including an array of mirrors each of which may be selectively controlled to be oriented in one of a first direction and a second direction;
a detector positioned so that mirrors within the digital micro-mirror device oriented in the first direction reflect incident light onto the detector and mirrors within the digital micro-mirror device oriented in the second direction do not, the detector configured to output a signal representative of an amount of light incident on the detector; and
a control system configured to apply M spatial patterns to the mirrors of the digital micro-mirror device, each of the M spatial patterns in synchronization with a corresponding pulse from the laser, and, for each of the M spatial patterns, to store sampled signal values from the output of the detector at each of K times following the corresponding pulse from the laser,
wherein the control system includes a processing system configured to reconstruct K images of the at least one object each using all M spatial patterns and stored sampled signal values corresponding to a respective one of the K times,
wherein the processing system is configured to search the K images for an object of interest among objects including the at least one object.

2. The apparatus according to claim 1 , further comprising an analog-to-digital device configured to selectively sample the output of the detector.

3. The apparatus according to claim 1 , wherein the M spatial patterns applied to the mirrors of the digital micro-mirror device are random patterns.

4. The apparatus according to claim 1 , wherein one of the K images reconstructed using stored sampled signal values corresponding to a time k within the K times corresponds to a predetermined range from the digital micro-mirror device.

5. The apparatus according to claim 1 , wherein each of the K images corresponds to a different range from the digital micro-mirror device.

6. The apparatus according to claim 5 , wherein the processing system is configured to determine a range to the object of interest based on which of the K images contains the object of interest.

7. The apparatus according to claim 1 , wherein each of the stored sampled signal values is associated within a memory of the processing system with an identification of the spatial pattern applied to the digital micro-mirror device at a time k at which the output of the detector was sampled.

8. The apparatus according to claim 7 , wherein each of the stored sampled signal values is associated within the memory of the processing system with an identification of the time k.

9. The apparatus according to claim 1 , wherein the mirrors within the digital micro-mirror device are partitioned into a 9×12 detector array.

10. The apparatus according to claim 1 , wherein between 10% and 20% of a number of pixels are sampled for a spatial resolution desired.

11. A method, comprising:
pulsing laser light from a laser to illuminate at least one object;
receiving laser light reflected from the at least one object at a digital micro-mirror device including an array of mirrors each of which may be selectively controlled to be oriented in one of a first direction and a second direction;
outputting, from a detector positioned so that mirrors within the digital micro-mirror device oriented in the first direction reflect incident light onto the detector and mirrors within the digital micro-mirror device oriented in the second direction do not, a signal representative of an amount of light incident on the detector;
applying M spatial patterns to the mirrors of the digital micro-mirror device, each of the M spatial patterns in synchronization with a corresponding pulse from the laser;
for each of the M spatial patterns, storing sampled signal values from the output of the detector at each of K times following the corresponding pulse from the laser;
reconstructing K images of the at least one object each using all M spatial patterns and stored sampled signal values corresponding to a respective one of the K times; and
searching the K images for an object of interest among objects including the at least one object.

12. The method according to claim 11 , further comprising selectively sampling the output of the detector with an analog-to-digital device.

13. The method according to claim 11 , wherein the M spatial patterns applied to the mirrors of the digital micro-mirror device are random patterns.

14. The method according to claim 11 , wherein one of the K images reconstructed using stored sampled signal values corresponding to a time k within the K times corresponds to a predetermined range from the digital micro-mirror device.

15. The method according to claim 11 , wherein each of the K images corresponds to a different range from the digital micro-mirror device.

16. The method according to claim 15 , further comprising determining a range to the object of interest based on which of the K images contains the object of interest.

17. The method according to claim 11 , wherein each of the stored sampled signal values is associated within a memory with an identification of the spatial pattern applied to the digital micro-mirror device at a time k at which the output of the detector was sampled.

18. The method according to claim 17 , wherein each of the stored sampled signal values is associated within the memory with an identification of the time k.

19. The method according to claim 11 , further comprising partitioning the mirrors within the digital micro-mirror device into a 9×12 detector array.

20. The method according to claim 11 , further comprising sampling between 10% and 20% of a number of pixels for a spatial resolution desired.

Assignees

• Raytheon Co

Inventors

• Fluckiger David U

Classifications

• G01S17/04 Primary

  Systems determining the presence of a target · CPC title

• G01S7/486

  Receivers · CPC title

• G01S17/89

  for mapping or imaging · CPC title

• G01S17/10

  using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) · CPC title

• G01S7/4816 Primary

  of receivers alone · CPC title