Detecting, tracking, and decoding pulse repetition frequency laser energy from laser designators

Patent metadata

Field	Value
Publication number	US-2016282179-A1
Application number	US-201514938409-A
Country	US
Kind code	A1
Filing date	Nov 11, 2015
Priority date	Mar 27, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A pulse repetition frequency detector, tracker, and decoder includes a two-dimensional InGaAs FPA of photodetectors configured to convert laser signals into electrical signals. A ROIC is operatively connected to the InGaAs FPA to condition electrical signals from the InGaAs FPA. A module is operatively connected to the ROIC to decode pulsed codes in the conditioned electrical signals and to provide output for tracking decoded laser spots in two-dimensional space. In another aspect, an imaging device includes an imager with an imaging FPA operatively connected to a first ROIC for imaging. A pulse repetition frequency detector, tracker, and decoder including a second ROIC as described above, is operatively connected to the first ROIC. The first and second ROICs are operatively connected to correlate the position of decoded laser spots in images from the imaging FPA.

First claim

What is claimed is:

1 . A pulse repetition frequency detector, tracker, and decoder system comprising:
a two-dimensional InGaAs FPA of photodetectors configured to convert laser signals into electrical signals; an ROIC operatively connected to the InGaAs FPA to condition electrical signals from the InGaAs FPA; and a module operatively connected to the ROIC to decode pulsed codes in the conditioned electrical signals and to provide output for tracking decoded laser spots in two-dimensional space.

2 . A decoder as recited in claim 1 , wherein the InGaAs FPA is configured to receive wavelengths up to and including 1700 nm.

3 . A decoder as recited in claim 1 , wherein the InGaAs FPA is configured to detect laser light of 1064 nm wavelength.

4 . A decoder as recited in claim 1 , wherein the InGaAs FPA is configured to detect laser light of 1550 nm wavelength.

5 . A decoder as recited in claim 1 , wherein the ROIC is configured to read from the InGaAs FPA at a frequency of at least 20 kHz.

6 . A decoder as recited in claim 1 , wherein the ROIC is operatively connected to the InGaAs FPA to condition electrical signals for tracking and decoding multiple laser spots at a time in the module.

7 . A decoder as recited in claim 1 , wherein the InGaAs FPA includes a plurality of rows and a plurality of columns of photodetectors.

8 . A decoder as recited in claim 1 , wherein the InGaAs FPA includes at least a 32 by 32 array of photodetectors.

9 . A decoder as recited in claim 1 , further comprising a filter assembly optically coupled to the InGaAs FPA of photodetectors to improve signal to noise ratio.

10 . A decoder as recited in claim 1 , wherein the module operatively connected to the ROIC includes machine readable instructions configured to instruct the module to:
receive signals from the ROIC for a series of images over time of pulsed energy reflected from the at least one target, each image including a plurality of pulses related to different first and second pulse codes; detect the pulses in an image of the received images; output pulse detection information including XY pixel coordinates and arrival time information associated with the respective detected pulses; associate the pulse detection information with a laser designator source; and generate output position information for the at least one target in space, the output position being based on the XY pixel coordinates and associated with the laser designator source.

11 . A decoder as recited in claim 10 , wherein the machine readable instructions include instructions configured to instruct the module to:
determine whether a distance between the associated XY pixel coordinates associated with one of the detected pulses relative to pulse detector information associated with a previously received detected pulse having the same pulse code is within a predetermined threshold value; and if so, validate pulse detector information associated with that one of the detected pulses.

12 . A decoder as recited in claim 1 , further comprising an output connector configured to connect to an imaging device for communication of decoded laser pulse data from the module to an imaging device.

13 . An imaging device comprising:
an imager including imaging FPA operatively connected to a first ROIC for imaging; and a pulse repetition frequency decoder operatively connected to the first ROIC, the decoder including:
a two-dimensional InGaAs FPA of photodetectors configured to convert laser signals into electrical signals; and
a second ROIC operatively connected to the InGaAs FPA to decode pulsed codes in electrical signals from the InGaAs FPA, wherein the first and second ROICs are operatively connected to correlate the position of decoded laser spots in images from the imaging FPA.

14 . An imaging device as recited in claim 13 , wherein the imaging FPA is configured for imaging in at least one of visible, thermal, or night vision.

15 . An imaging device as recited in claim 13 , wherein the InGaAs FPA is configured to receive wavelengths up to and including 1700 nm.

Assignees

• Sensors Unlimited Inc

Inventors

• Nazemi Jonathan
• Rozploch Robert
• Barby John P
• Eckhardt Andrew

Classifications

• G01J2001/4238

  Pulsed light · CPC title

• F41G7/2293

  using electromagnetic waves other than radio waves · CPC title

• F41G3/145 Primary

  using a target illuminator · CPC title

• G01S3/784

  using a mosaic of detectors · CPC title

• G01S17/66 Primary

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