Active pushbroom scanning system and method

Patent metadata

Field	Value
Publication number	US-2018124342-A1
Application number	US-201615335886-A
Country	US
Kind code	A1
Filing date	Oct 27, 2016
Priority date	Oct 27, 2016
Publication date	May 3, 2018
Grant date	—

Abstract

Aspects and embodiments are generally directed to active imaging systems and methods. In one example, an active imaging system includes a positioning system configured to detect a direction of motion of the imaging system relative to a scene, an optical source positioned to emit electromagnetic radiation, a non-mechanical beamsteering device positioned to receive the electromagnetic radiation from the optical source and configured to scan the electromagnetic radiation over at least a first portion of the scene within an instantaneous field-of-view of an optical receiver, and the optical receiver positioned to receive reflections of the electromagnetic radiation from at least the first portion of the scene within the instantaneous field-of-view, wherein the first portion of the scene is within a first edge region of the instantaneous field-of-view of the optical receiver, the first edge region being in the direction of motion of the imaging system.

First claim

What is claimed is:

1 . An active imaging system comprising:
a positioning system configured to detect a direction of motion of the imaging system relative to a scene to be imaged; an optical source positioned to emit electromagnetic radiation along a transmit path; a non-mechanical beamsteering device positioned along the transmit path to receive the electromagnetic radiation from the optical source and configured to scan the electromagnetic radiation over at least a first portion of the scene within an instantaneous field-of-view of an optical receiver; and the optical receiver positioned to receive reflections of the electromagnetic radiation from at least the first portion of the scene within the instantaneous field-of-view, wherein the first portion of the scene is within a first edge region of the instantaneous field-of-view of the optical receiver, the first edge region being in the direction of motion of the imaging system.

2 . The active imaging system according to claim 1 , wherein the optical receiver is a focal plane array including a plurality of pixels arranged in a series of rows and columns.

3 . The active imaging system according to claim 2 , further comprising a Read-Out Integrated Circuit (ROIC) coupled to the focal plane array and configured to activate a subset of the plurality of pixels of the focal plane array to receive the reflections of the electromagnetic radiation, wherein the subset of the plurality of pixels corresponds to the first edge region of the instantaneous field-of-view.

4 . The active imaging system according to claim 3 , wherein the subset of the plurality of pixels includes at least one of a single row of pixels or a single column of pixels.

5 . The active imaging system according to claim 1 , further comprising control circuitry coupled to the positioning system, the control circuitry configured to locate the first portion of the scene within the instantaneous field-of-view of the optical receiver based at least in part on the direction of motion of the imaging system.

6 . The active imaging system according to claim 5 , wherein the positioning system is further configured to detect the direction of motion within a first single-dimensional direction within a plane of the optical receiver, and wherein the first edge region of the instantaneous field-of-view is in the direction of motion of the imaging system within the first single-dimensional direction.

7 . The active imaging system according to claim 6 , wherein the positioning system is further configured to detect the direction of motion within a two-dimensional direction, and wherein the two-dimensional direction includes the first single-dimensional direction and a substantially orthogonal second single-dimensional direction within the plane of the optical receiver.

8 . The active imaging system according to claim 7 , wherein the non-mechanical beamsteering device is further configured to scan the electromagnetic radiation over at least a second portion of the scene, and wherein the second portion of the scene corresponds to a second edge region of the instantaneous field-of-view of the optical receiver in the direction of motion of the imaging system within the second single-dimensional direction.

9 . The active imaging system according to claim 5 , wherein the control circuitry is coupled to the optical receiver and further configured to generate a plurality of images of the scene, wherein at least one image of the plurality is a composition of an image of the first portion of the scene and a previous image.

10 . The active imaging system according to claim 5 , wherein the optical receiver is further configured to collect at least one Bidirectional Reflectance Distribution Function (BRDF) sample.

11 . The active imaging system according to claim 1 , wherein the positioning system includes a global positioning system (GPS).

12 . The active imaging system according to claim 1 , wherein the non-mechanical beamsteering device includes a liquid crystal waveguide.

13 . The active imaging system according to claim 1 , wherein the optical source includes an active laser source configured to emit shortwave infrared (SWIR) radiation in a wavelength range of approximately 0.9-1.7 micrometers.

14 . The active imaging system according to claim 1 , further comprising control circuitry coupled to the optical receiver and configured to generate a plurality of images of the scene, wherein the positioning system is configured to detect the direction of motion of the imaging system relative to the scene based at least in part on a variation of a feature within the scene between a first image of the plurality and a second image of the plurality.

15 . A method of optical imaging, the method comprising:
detecting a direction of motion relative to a scene to be imaged; emitting electromagnetic radiation from an optical source along a transmit path; scanning the electromagnetic radiation over at least a first portion of the scene, the first portion of the scene corresponding to a first edge region of an instantaneous field-of-view of an optical receiver, in the direction of motion; and receiving, within the instantaneous field-of-view of the optical receiver, reflections of the electromagnetic radiation from at least the first portion of the scene.

16 . The method according to claim 15 , further comprising activating a subset of a plurality of pixels of the optical receiver to receive the reflections of the electromagnetic radiation, wherein the subset of the plurality of pixels corresponds to the first edge region of the instantaneous field-of-view.

17 . The method according to claim 16 , wherein activating the subset of the plurality of pixels includes activating at least one of a single row of pixels or a single column of pixels of the optical receiver.

18 . The method according to claim 15 , wherein detecting the direction of motion includes detecting the direction of motion within a first single-dimensional direction within a plane of the optical receiver, and wherein the first edge region of the instantaneous field-of-view is in the direction of motion within the first single-dimensional direction.

19 . The method according to claim 18 , wherein detecting the direction of motion includes detecting the direction of motion within a two-dimensional direction, and wherein the two-dimensional direction includes the first single-dimensional direction and a substantially orthogonal second single-dimensional direction within the plane of the optical receiver.

20 . The method according to claim 19 , further comprising:
scanning the electromagnetic radiation over at least a second portion of the scene, wherein the second portion of the scene corresponds to a second edge region of the instantaneous field-of-view of the optical receiver in the direction of motion within the second single-dimensional direction.

Assignees

• Raytheon Co

Inventors

• Uyeno Gerald P
• Keller Sean D

Classifications

• H04N23/56 Primary

  provided with illuminating means · CPC title

• H04N3/10 Primary

  by means not exclusively optical-mechanical (H04N3/36 takes precedence) · CPC title

• H04N25/441

  by reading contiguous pixels from selected rows or columns of the array, e.g. interlaced scanning · CPC title

• G01S17/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G06T7/246

  using feature-based methods, e.g. the tracking of corners or segments · CPC title