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JP-7856420-B2 - Composite multispectral polarization sensor

JP7856420B2JP 7856420 B2JP7856420 B2JP 7856420B2JP-7856420-B2

Inventors

  • ゲルウェ， デーヴィッド ロデリック
  • イデル， ポール エス．
  • パクストン， ケヴィン レイ
  • クンツラー， フリードリヒ ダブリュ．

Assignees

  • ザ・ボーイング・カンパニー

Dates

Publication Date
20260511
Application Date
20211217
Priority Date
20201219

Claims (15)

  1. A composite multiple spectral polarization (CMSP) sensor (100), A camera (112) having a single focal plane array (FPA) (106 , 300 ) equipped with multiple detectors (110, 302), A multispectral polarization (MSP) filter (104, 400) comprising a series of spectral filters (402) and a series of polarizing filters (404), wherein the series of spectral filters (402) comprises at least a first band filter (418) having a first frequency range and a second band filter (420) having a second frequency range different from the first frequency range, and the series of polarizing filters (404) comprises at least a first polarizing filter (406) having a first polarization value and a second polarizing filter (408) having a second polarization value different from the first polarization value, A controller (108) that communicates with the MSP filter (104, 400) and the single FPA (106, 300), wherein the controller (108) is configured to initiate capture (702) of a first image (806) of the scene (114, 606) while a specific portion (128) of the scene (114, 606) has a first alignment (800) with the first detector (306) of the single FPA (106, 300), and the first band filter (418) is between the specific portion (128) of the scene (114, 606) and the first detector (306), and the specific portion of the scene (114, 606) has a first alignment (800) with the single FPA In response to the determination (706) that A (106, 300) has a second detector (308) and a second alignment (802), the second alignment (802) substantially coincides with the first alignment (800), and the second band filter (420) is between the second portion of the scene (114, 606) and the second detector (308), the storage (710) of the second image (808) of the scene (114, 606) is initiated, wherein the particular portion of the scene (114, 606) is captured while having the second detector (308) and the second alignment (802), and the particular portion (128) of the scene (114, 606) is , in response to a determination (712) that the single FPA (106, 300) has a third detector (310) and a third alignment (804), the third alignment (804) substantially coincides with the first alignment (800), and the first polarizing filter (406) is between the particular portion (128) of the scene (114, 606) and the third detector (310), the storage (716) of the third image (810) of the scene (114, 606) is initiated, and at least the first A controller (108) generates a multispectral polarization composite image (116) using the first image (806), the second image (808), and the third image (810), which are aligned with subpixel precision , by adding them pixel by pixel to construct the multispectral polarization composite image (116) as a hypercube image, thereby increasing the contrast-to-noise ratio (CNR) of the multispectral polarization composite image (116). A composite multispectral polarization (CMSP) sensor (100) is provided with the following features.
  2. The first frequency range is associated with a first color, and the second frequency range is associated with a second color different from the first color. The MSP filter (104, 400) includes a composite type spectral filter (402) comprising the series of spectral filters and the series of polarizing filters (404), wherein the first and second band filters of the series of spectral filters have a frequency range that varies from infrared (IR) frequencies to ultraviolet frequencies. The CMSP sensor (100) according to claim 1, wherein the series of polarizing filters (404) has a polarization range selected from the group consisting of vertical polarization, horizontal polarization, +45 degree polarization, -45 degree polarization, linear polarization angle by other options, left-hand circular polarization, and right-hand circular polarization.
  3. The controller is further configured such that the position of one or more components of the CMSP sensor is adjusted to produce a second alignment between the specific portion of the scene and the second detector. The CMSP sensor (100) according to claim 1 or 2, wherein the MSP filter comprises a filter array, and the controller is configured to adjust the position of one or more components of the CMSP sensor by shifting the position of the filter array based on the physical dimensions of the first band filter, and the first detector and the second detector are the same detector.
  4. A CMSP sensor (100) according to any one of claims 1 to 3, further comprising a telescope (118) that communicates signals with the MSP filter and the controller, and an optical line-of-sight measuring device (120) configured to generate line-of-sight (LOS) movement data of an optical sensor, wherein the LOS measuring device includes an inertial measuring unit (IMU ) .
  5. The CMPS sensor (100) according to any one of claims 1 to 4, further comprising a telescope (118) that communicates signals with the MSP filter and the controller , the CMPS sensor further comprising a motion device ( 122) configured to physically move and orient the telescope toward the scene , and a motion detector (124) configured to measure the movement of the telescope.
  6. The CMSP sensor (100) according to any one of claims 1 to 5, wherein the CMSP sensor (100) generates a first image (806) by positioning a target of the FPA (200) at a first position oriented toward the scene (606), and generates a second image (808) by positioning a target of the FPA (200) at a second position oriented toward the scene (606).
  7. The CMSP sensor (100) according to any one of claims 1 to 6, wherein the second detector is the first detector (306), and the second alignment corresponds to the first alignment (800) where the second band filter (420) is located between the specific portion (128) of the scene (114, 606) and the first detector (306), the first band filter (418) is shifted away from the first detector (306), and the second band filter (420) is shifted to be located above the first detector (306).
  8. The CMSP sensor (100) according to any one of claims 1 to 7, wherein the first image (806), the second image (808), and the third image (810) are registered to generate the first alignment (800), the second alignment (802), and the third alignment (804).
  9. The CMSP sensor (100) according to any one of claims 1 to 8, wherein the CMSP sensor is configured on a mobile platform (102) selected from the group consisting of satellites, spacecraft, aircraft, unmanned aerial vehicles, and ships.
  10. A CMSP sensor (100) according to any one of claims 1 to 9, further comprising a single focal plane array (FPA) (106) comprising multiple detectors (110).
  11. A method for capturing image data (700), wherein the method is The method includes capturing a first image (806) of a scene (114, 606) by a composite multiplespectral polarization (CMSP) sensor (100) while a specific portion (128) of a scene (114, 606) has a first detector (306) and a first alignment (800) of a single focal plane array (FPA) (106, 300), and a first band filter (418) is between the specific portion (128) of the scene (114, 606) and the first detector (306), In response to the determination (706) that the particular portion of the scene (114, 606) has a second detector (308) and a second alignment (802) of the single FPA (106, 300), the second alignment (802) substantially coincides with the first alignment (800), and the second bandfilter (420) is between the particular portion (128) of the scene (114, 606) and the second detector (308), the storage (710) of the second image (808) of the scene (114, 606) is initiated, which is a second image (808) of the scene (114, 606) captured while the particular portion of the scene (114, 606) has the second detector (308) and the second alignment (802), In response to the determination (712) that the particular portion (128) of the scene (114, 606) has a third detector (310) and a third alignment (804) of the single FPA (106, 300), the third alignment (804) substantially coincides with the first alignment (800), and the first polarizing filter (406) is between the particular portion (128) of the scene (114, 606) and the third detector (310), the storage (716) of the third image (810) of the scene (114, 606) is initiated, which is a third image (810) of the scene (114, 606) captured while the particular portion (128) of the scene (114, 606) has the third detector (310) and the third alignment (804), A method for capturing image data (700) comprising generating a multispectral polarization composite image (116) (720) using at least the first image (806), the second image (808), and the third image (810), and adding the first image (806), the second image (808), and the third image (810), which are aligned with subpixel precision, pixel by pixel to construct the multispectral polarization composite image (116) as a hypercube image, thereby increasing the contrast-to-noise ratio (CNR) of the multispectral polarization composite image (116).
  12. The method according to claim 11 (700), wherein a first frequency range is associated with a first color, and a second frequency range is associated with a second color different from the first color, and the MSP filter (104, 400) includes a composite type spectral filter (402) comprising a series of spectral filters and a series of polarizing filters (404), the first and second band filters of the series of spectral filters having a frequency range that varies from infrared (IR) frequencies to ultraviolet frequencies, and the polarizing filters of the series of polarizing filters (404) having a polarization range selected from the group consisting of vertical polarization, horizontal polarization, +45 degree polarization, and -45 degree polarization.
  13. The method according to claim 11 or 12 (700), further comprising adjusting one or more components of the CMSP sensor (100) to generate a second alignment between the specific portion of the scene (114, 606) and the second detector (308).
  14. The method according to any one of claims 11 to 13 (700), wherein the second detector is the first detector (306), the second alignment corresponds to the first alignment (800) where the second bandfilter (420) is between the specific portion (128) of the scene (114, 606) and the first detector (306), the first bandfilter (418) is shifted away from the first detector (306), and the second bandfilter (420) is shifted to be positioned above the first detector (306).
  15. The method according to any one of claims 11 to 14 (700), wherein the first image (806), the second image (808), and the third image (810) are registered to generate the first alignment (800), the second alignment (802), and the third alignment (804).

Description

Imaging systems utilizing electro-optic sensors can be used to determine one or more characteristics of an object when the electro-optic sensor receives electromagnetic radiation signals from or reflected by the object. Multispectral sensors are electro-optic sensors that capture images of electromagnetic radiation at multiple wavelengths. These multispectral sensors can be used in several different cameras that capture images of red, green, blue, and intermediate wavelengths, as well as ultraviolet (UV) and infrared (IR) wavelengths. Generally, the use of such multispectral sensors in multispectral imaging is useful for many applications, including topographic classification, detection of specific substances (minerals, paints, metals, vehicles, roads, building materials, oil spills, soil types, etc.), and characterization of the atmosphere, clouds, weather, and climate. To improve these types of image sensors, polarization sensors are also included. Polarized images utilize a polarization sensor that divides the received light in the captured image into various polarization planes (e.g., vertical, horizontal, and 45-degree polarization channels). Because artificial materials tend to polarize light more strongly than natural materials, by properly processing these polarization channels, it is possible to generate linearly polarized degree (DOLP) images that "pop out" artificial objects from the noisy background of the captured image. Unfortunately, known types of image sensors that utilize both multispectral and polarization sensors are complex, requiring separate cameras and one or more optical beam splitters to split the image light captured from a light collector (i.e., a telescope) into different spectral bands and polarization channels. In embodiments of this operation, a portion of the collected image light is directed through a focusing optical system to a first camera acting as a multispectral image sensor, and another portion of the collected image light is directed to another camera acting as a polarization image sensor. In this embodiment, each camera is implemented as a focal plane array (FPA), and these known image systems utilize a combined optical system and at least two FPAs. Thus, there is a need for a new type of image sensor that can provide multispectral and polarized images without requiring complex optical systems or multiple FPAs. A composite multispectral polarization (CMSP) sensor is disclosed. The CMSP sensor comprises a multispectral polarization (MSP) filter, a single focal plane array (FPA), and a controller. The FPA comprises a plurality of detectors, and the MSP filter comprises a first band filter having at least a first frequency range, a second band filter having a second frequency range different from the first frequency range, a first polarizing filter having a first polarization state, and a second polarizing filter having a second polarization state different from the first polarization state. The controller communicates signals with the MSP filter and the single FPA, and the controller A specific portion of the scene has a first detector and a first alignment of a single FPA, and while the first band filter is between the specific portion of the scene and the first detector, the capture of a first image of the scene, which is the first image (806) to be registered, is initiated. In response to determining that a specific portion of the scene has a second detector and a second alignment of a single FPA, and the second alignment substantially coincides with the first alignment, and that a second bandfilter is located between the specific portion of the scene and the second detector, the storage of the second image of the scene captured while the specific portion of the scene has the second detector and the second alignment is initiated. In response to determining that a specific portion of the scene has a third detector and a third alignment of a single FPA, the third alignment substantially coincides with a first alignment, and that a first polarization filter is located between the specific portion of the scene and the third detector, a third image of the scene is captured while the specific portion of the scene has the third detector and the third alignment, and saving of the third image to be registered is initiated. The system is configured to generate a multispectral polarization composite image using at least a first image, a second image, and a third image, and to construct the multispectral polarization composite image as a hypercube image by co-adding the first image, the second image, and the third image, thereby increasing the contrast-to-noise ratio (CNR) of the multispectral polarization composite image. Other devices, apparatus, systems, methods, features, and advantages of the concepts described herein will be apparent to those skilled in the art by examining the drawings and detailed description below. All such additional devices, apparatus, systems, met