Six dimensional tracking of sparse LADAR data

Patent metadata

Field	Value
Publication number	US-12153139-B2
Application number	US-202017138386-A
Country	US
Kind code	B2
Filing date	Dec 30, 2020
Priority date	Dec 30, 2020
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

An apparatus, and method of operating the same processes of LADAR data including iterating back and forth between target detection in a 2-D array having range and range rate dimension, and a 4-D array having azimuth, azimuthal velocity, elevation, & elevation velocity dimensions. The apparatus includes a receiver and a processor arranged to generate photo events including target signal photo events and background photo events, transform the photo events into the 2-D target tracking array including range and range-rate parameters and tag photo events determined to be 2-D target signal photo events. The processor transforms tagged photo events into the 4-D target and tags photo events determined to be 4-D target signal photo events.

First claim

What is claimed is:

1. A laser detection and ranging system comprising:
a receiver arranged to receive scattered laser pulses; and
a processor arranged to:
A. generate photo events based on the received scattered laser pulses, the photo events including target signal photo events and background photo events,
B. transform the photo events into a two dimensional 2-D target tracking array including range and range-rate parameters resulting in 2-D photo events, discard photo events determined to be a subset of the background photo events based on corresponding 2-D photo events of the 2-D photo events, and tag photo events determined to be 2-D target signal photo events, and
C. transform photo events tagged as 2-D target signal photo events into a four dimensional 4-D target tracking array including azimuth, azimuthal rate, elevation, and elevation rate parameters resulting in 4-D photo events, discard photo events determined to be a further subset of the background photo events based on corresponding 4-D photo events of the 4-D photo events, and tag photo events determined to be 4-D target signal photo events.

2. The laser detection and ranging system of claim 1 , wherein the processor repeats steps B and C for a plurality of iterations, and wherein, after a first iteration of the plurality of iterations, the photo events transformed in step B are the tagged 4-D target signal photo events from step C of an immediately previous iteration of the plurality of iterations.

3. The laser detection and ranging system of claim 1 , comprising storing the parameters associated with each of the tagged 4-D target signal photo events in a memory.

4. The laser detection and ranging system of claim 3 , wherein the parameters are stored in memory to represent a six dimensional (6D) array.

5. The laser detection and ranging system of claim 4 , wherein the parameters include range, range-rate, azimuth, azimuthal rate, elevation, and elevation rate.

6. The laser detection and ranging system of claim 1 , wherein the processor determines that photo events with a signal strength lower than a detection threshold are the background photo events.

7. The laser detection and ranging system of claim 6 , wherein the detection threshold includes a statistically significant photo event.

8. The laser detection and ranging system of claim 6 , wherein the detection threshold applied in step B is different than a detection threshold applied in step C.

9. The laser detection and ranging system of claim 1 further comprising a laser transmitter arranged to emit laser pulses toward a target.

10. The laser detection and ranging system of claim 1 , wherein the photo events include sparse video data.

11. A method for laser detection and ranging comprising:
A. receiving scattered laser pulses
B. generating photo events based on the received scattered laser pulses, the photo events including target signal photo events and background photo events,
C. transforming the photo events into a two dimensional 2-D target tracking array including range and range-rate parameters resulting in 2-D photo events, discarding photo events determined to be a subset of the background photo events based on corresponding 2-D photo events of the 2-D photo events, and tagging photo events determined to be 2-D target signal photo events, and
D. transforming photo events tagged as 2-D target signal photo events into a four dimensional (4-D) target tracking array including azimuth, azimuthal rate, elevation, and elevation rate parameters resulting in 4-D photo events, discarding photo events determined to be a further subset of the background photo events based on corresponding 4-D photo events of the 4-D photo events, and tagging photo events determined to be 4-D target signal photo events.

12. The method of claim 11 , comprising repeating steps C and D for a plurality of iterations, and wherein, after a first iteration of the plurality of iterations, the photo events transformed in step C are the tagged 4-D target signal photo events from step D of an immediately previous iteration of the plurality of iterations.

13. The method of claim 11 , comprising storing the parameters associated with each of the tagged 4-D target signal photo events in a memory.

14. The method of claim 13 , wherein the parameters are stored in memory to represent a six dimensional (6D) array.

15. The method of claim 14 , wherein the parameters include range, range-rate, azimuth, azimuthal rate, elevation, and elevation rate.

16. The method of claim 11 , discarding photo events determined to be background photo events includes comparing a signal strength of the photo events to a detection threshold and discarding photo events having a signal strength lower than the detection threshold as the background photo events.

17. The method of claim 16 , wherein the detection threshold includes a statistically significant photo event.

18. The method of claim 16 , wherein the detection threshold applied in step C is different than a detection threshold applied in step D.

19. A LADAR sparse state-space carving system comprising:
a receiver arranged to receive scattered laser pulses and generate photo events based on the received scattered laser pulses, the photo events including target signal photo events and background photo events,
a two dimensional 2-D target tracking detector arranged to transform the photo events into a 2-D target tracking array including range and range-rate parameters resulting in 2-D photo events, discard photo events determined to be a subset of the background photo events, and tag photo events determined to be 2-D target signal photo events based on corresponding 2-D photo events of the 2-D photo events, and
a four dimensional 4-D target tracking detector arranged to transform photo events tagged as 2-D target signal photo events into a 4-D target tracking array including azimuth, azimuthal rate, elevation, and elevation rate parameters resulting in 4-D photo events, discard photo events determined to be a further subset of the background photo events based on corresponding 4-D photo events of the 4-D photo events, and tag photo events determined to be 4-D target signal photo events.

20. The system of claim 19 , wherein the 2-D target tracking detector and the 4-D target tracking detector transform the photo events iteratively over a plurality of iterations, and wherein, after a first iteration of the plurality of iterations, the photo events input into and transformed by the 2-D target tracking detector are the tagged 4-D target signal photo events from the 4-D target tracking detector during an immediately previous iteration of the plurality of iterations.

Assignees

• Raytheon Co

Inventors

• Greenberg Adam Hodge
• Marcus Eran

Classifications

• G01S7/4814

  of transmitters alone · CPC title

• G01S7/4861

  Circuits for detection, sampling, integration or read-out · CPC title

• G01S7/4808

  Evaluating distance, position or velocity data · CPC title

• G01S17/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title

• G01S17/66

  Tracking systems using electromagnetic waves other than radio waves · CPC title