Estimating a source location of a projectile

Patent metadata

Field	Value
Publication number	US-11119178-B2
Application number	US-201815988302-A
Country	US
Kind code	B2
Filing date	May 24, 2018
Priority date	Apr 25, 2012
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

According to examples of the presently disclosed subject matter, there is provided a system for estimating a source location of a projectile, comprising an optics an optics subsystem, a radar subsystem and a processor. The processor is adapted to use range and velocity measurements obtained from data provided by the radar subsystem, a source direction and an event start time obtained from data provided by the optical subsystem and a predefined kinematic model for the projectile for estimating a range to a source location of the projectile.

First claim

The invention claimed is:

1. A system, comprising:
an optics subsystem;
a radar subsystem;
a Faraday cage;
a processor;
wherein the optics subsystem and the radar subsystem are substantially co-located, and
wherein the optics subsystem is installed within said Faraday cage which enables electromagnetic isolation of the optics subsystem from electromagnetic interferences (EMI) and/or radio frequency interferences (RFI) created by operation of the radar subsystem,
wherein the optics subsystem comprises a detection module adapted for acquiring at least one of (i) and (ii):
(i) a first image in a first optical spectrum band comprising potassium (K) doublet emission lines or Sodium (N) emission lines, and a second image in a second optical spectrum band different from the first optical spectrum band;
(ii) a first image in “Red-band” within MWIR spectral band, and a second image in other sub-bands of the MWIR spectral band, different from the “Red-band”;
wherein the processor is configured to determine a difference between pixels of the first image and pixels of the second image,
wherein the processor is configured to apply feature extraction to imaged scenery captured by the optics subsystem to identify a feature in the imaged scenery and determine a direction towards the identified feature.

2. The system of claim 1 , wherein electrical leads of the optics system are located within the Faraday cage.

3. The system of claim 1 , wherein the optics subsystem and the radar subsystem are co-registered.

4. The system of claim 1 , wherein the optics subsystem and the radar subsystem are timely synchronized.

5. The system of claim 1 , comprising a processor configured for processing measurements from the optics subsystem and the radar subsystem.

6. The system of claim 5 , wherein the processor is configured to utilize measurements from the radar subsystem to process range and velocity measurements for pixels of imaged scenery captured by the optics subsystem.

7. The system of claim 5 , wherein the processor is configured to take into account one or more of the following: an optical geometrical distortion of the optics subsystem, a line of sight misalignment between the radar subsystem and the optics subsystem; an optics subsystem response latency; spatial non-uniformity of the measurements; and an optical spot Centroid estimation of the optics subsystem.

8. The system of claim 1 , wherein the processor is configured to perform co registration operation comprising:
obtaining, from the radar subsystem, radar measurements of radar calibration objection object positioned at a far-field range;
obtaining, from the optics subsystem, optical measurements of an optical calibration object configured to provide an optical signal at spectral band(s) detectable by the optics subsystem; and
utilizing said radar measurements and said optical measurements to determine registration between the radar subsystem and the optics subsystem.

9. The system of claim 8 , wherein said radar calibration objection object is co-positioned with the optical calibration object.

10. The system of claim 8 , wherein said radar calibration objection object and said optical calibration object are placed at different known locations; and
wherein the viewing direction of the radar calibration objection object from the radar subsystem, and viewing direction of the optical calibration object from the optics subsystem is used to correct direction findings of the radar subsystem and the optics subsystem, and thereby determine registration between them.

11. The system of claim 8 , wherein said optical calibration object is light emitter providing modulated light; and wherein co-registration operation comprises image processing utilizing said modulation to reduce errors induced by atmospheric path turbulence and/or for optical aberrations of the optics subsystem.

12. The system of claim 11 , wherein said optical calibration object generates optical signal during short periods of time.

13. A system, comprising:
an optics subsystem;
a radar subsystem;
wherein the optics subsystem comprises one or more cameras configured to acquire at least one of (i) and (ii):
(i) a first image in a first optical spectrum band comprising potassium (K) doublet emission lines or Sodium (N) emission lines, and a second image in a second optical spectrum band different from the first optical spectrum band;
(ii) a first image in “Red-band” within MWIR spectral band, and a second image in other sub-bands of the MWIR spectral band, different from the “Red-band”;
a processor configured for processing measurements from the optics subsystem and the radar subsystem;
wherein the processor is configured to:
utilize measurements from the radar subsystem to process range and velocity measurements for pixels of imaged scenery captured by the optics subsystem; and
determine a difference between pixels of the first image and pixels of the second image captured by the optics subsystem,
identify one or more features in the imaged scenery based on said difference, and
determine a direction towards the one or more identified features.

14. A system, comprising:
an optics subsystem located at a first position;
a radar subsystem located at a second position substantially co-located with the first position; and
a processor configured for processing measurements from the optics subsystem and the radar subsystem;
wherein the processor is configured to perform co-registration operation between the substantially co-located optics subsystem and radar subsystem, the co-registration operation comprising:
obtaining, from the radar subsystem, radar measurements of radar calibration objection object positioned at a far-field range;
obtaining, from the optics subsystem, optical measurements of an optical calibration object configured to provide an optical signal at spectral band(s) detectable by the optics subsystem;
utilizing said radar measurements and said optical measurements to determine co-registration between a direction of the radar subsystem and a direction of the optics subsystem; and
wherein said optical calibration object is light emitter providing modulated light; and wherein said co-registration operation comprises image processing utilizing said modulation to determine position of the optical calibration object, said image processing comprising performing a difference between at least two different images of the optical calibration object acquired by the optics subsystem located at the first position, to reduce errors induced by atmospheric path turbulence and/or for optical aberrations of the optics subsystem.

Assignees

• Elta Systems Ltd

Inventors

• Tidhar Gil

Classifications

• G01S13/867 Primary

  Combination of radar systems with cameras · CPC title

• G01S3/782

  Systems for determining direction or deviation from predetermined direction · CPC title

• G01S7/4972

  Alignment of sensor · CPC title

• G01S13/582

  adapted for simultaneous range and velocity measurements · CPC title

• G01S13/86

  Combinations of radar systems with non-radar systems, e.g. sonar, direction finder · CPC title