Indirect self-imaging systems and methods

Patent metadata

Field	Value
Publication number	US-10647449-B2
Application number	US-201815993570-A
Country	US
Kind code	B2
Filing date	May 30, 2018
Priority date	May 30, 2018
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

According to an embodiment, a system includes a controller configured to determine a set of background light intensities associated with a satellite, where each background light intensity corresponds to at least one of an orientation and a position of a light source relative to the satellite, to determine a set of relative orientations of the light source corresponding to the set of background light intensities, and to generate an image of the satellite based, at least in part, on the determined set of background light intensities and the determined set of relative orientations of the light source.

First claim

The invention claimed is:

1. A system, comprising:
a controller ( 112 , 131 ) configured to:
determine ( 502 ) a set of background light intensities associated with a satellite ( 110 , 210 ), wherein each background light intensity corresponds to at least one of an orientation and a position of a light source ( 320 , 330 ) relative to the satellite;
determine ( 504 ) a set of relative orientations of the light source ( 322 , 324 , 332 , 334 ) corresponding to the set of background light intensities; and
generate ( 506 ) an image ( 352 , 452 ) of the satellite based, at least in part, on the determined set of background light intensities and the determined set of relative orientations of the light source.

2. The system of claim 1 , wherein:
the satellite comprises an optical sensor ( 140 , 142 , 144 ) coupled to the satellite and configured to provide celestial image data corresponding to at least one of an orientation and a position of the satellite;
the determining the set of background light intensities is based, at least in part, on the celestial image data provided by the optical sensor; and
the light source is outside a field of view of the optical sensor and the set of relative orientations of the light source are relative to a focal plane assembly ( 242 ) of the optical sensor or relative to the satellite.

3. The system of claim 2 , wherein:
the optical sensor comprises a first optical sensor, the celestial image data comprises first celestial image data, the field of view comprises a first field of view, and the focal plane assembly comprises a first focal plane assembly;
the satellite comprises a second optical sensor ( 140 , 142 , 144 ) coupled to the satellite and configured to provide additional celestial image data corresponding to the orientation or position of the satellite, substantially simultaneously with the first optical sensor providing the first celestial image data;
the determining the set of background light intensities is based, at least in part, on the first and additional celestial image data; and
the set of relative orientations of the light source are relative to at least one of the focal plane assembly ( 242 ) of the first optical sensor, the satellite, and the second optical sensor.

4. The system of claim 1 , wherein:
the satellite comprises a temperature monitoring system ( 143 ) comprising a plurality of temperature sensors each coupled to or within the satellite and each configured to provide temperature data corresponding to a portion of the satellite;
the determining the set of background light intensities corresponding to the satellite is based, at least in part, on the temperature data provided by the temperature monitoring system; and
the set of relative orientations of the light source are relative to the satellite.

5. The system of claim 1 , wherein the determining the set of relative orientations of the light source comprises:
receiving ( 512 ) a set of time stamps and a set of orientations or positions of the satellite corresponding to the set of background light intensities; and
determining ( 504 ) the set of relative orientations of the light source by transforming ( 514 ) the set of orientations or positions of the satellite into the set of relative orientations of the light source based, at least in part, on a known time correspondence of the set of orientations or positions of the satellite to the set of relative orientations of the light source.

6. The system of claim 1 , wherein the determining the set of relative orientations of the light source comprises:
receiving ( 516 ) a set of orientation or position measurements of the light source from a light source sensor ( 144 ) coupled to the satellite; and
determining ( 504 ) the set of relative orientations of the light source by transforming ( 518 ) the set of orientation or position measurements of the light source into the set of relative orientations of the light source based, at least in part, on a known spatial correspondence of the set of orientation or position measurements of the light source to the set of relative orientations of the light source.

7. The system of claim 1 , wherein the generating the image of the satellite comprises:
determining ( 522 ) a set of pixel positions within the image based on the set of relative orientations of the light source; and
determining ( 528 ) a corresponding set of pixel values based, at least in part, on the determined set of background light intensities.

8. The system of claim 7 , wherein the light source is the Sun, the determining ( 502 ) the set of background light intensities is based, at least in part, on celestial image data provided by a star tracker ( 142 ) coupled to the satellite, and the determining the corresponding set of pixel values comprises:
subtracting ( 524 ) a bias value associated with the star tracker from each background light intensity in the set of background light intensities to generate a set of bias corrected background light intensities; and
scaling ( 526 ) the set of bias corrected background light intensities according to a light shield attenuation function associated with the star tracker, wherein the light shield attenuation function is configured to provide an attenuation scale factor based, at least in part, on at least one of a relative orientation of the Sun to the star tracker and a pixel location in the celestial image data corresponding to a background light intensity.

9. The system of claim 1 , wherein the controller is configured to:
determine ( 530 ) an attitude maneuver configured to increase or decrease at least one of a relative elevation range and a relative azimuth range corresponding to the determined set of relative orientations; and
provide ( 532 ) the attitude maneuver to an attitude control system ( 126 ) of the satellite before the determining the set of background light intensities.

10. The system of claim 1 , wherein the controller is configured to:
determine ( 508 ) an operational status of the satellite based on the generated image, wherein the operational status of the satellite comprises one or more of a deployment status of the satellite and a surface status of the satellite.

11. A method comprising:
determining ( 502 ) a set of background electromagnetic radiation “EMR” intensities associated with a satellite ( 110 , 210 ), wherein each background EMR intensity corresponds to at least one of an orientation and a position of an EMR source ( 130 , 320 , 330 ) relative to the satellite;
determining ( 504 ) a set of relative orientations of the EMR source ( 322 , 324 , 332 , 334 ) corresponding to the set of background EMR intensities; and
generating ( 506 ) an image ( 352 , 452 ) of the satellite based, at least in part, on the determined set of background EMR intensities and the determined set of relative orientations of the EMR source.

12. The method of claim 11 , wherein:
the background EMR intensities comprise background light intensities and the EMR source comprises a light source;
the satellite comprises an optical sensor ( 140 , 142 , 144 ) coupled to the satellite and configured to provide celestial image data corresponding to at least one of an orientation and a position of the satellite;
the determining the set of background light intensities is based, at least in part, on the celestial image data provided by the optical sensor; and
the light source is outside a field of view of the optical sensor and the set of relative orientations of the light source are relative to a focal plane assembly ( 242 ) of the optical sensor or relative to the satellite.

13. The method of claim 12 ,

Assignees

• Boeing Co

Inventors

• Wasson Christopher James
• Taylor Bradley Whitten
• Fowell Richard A

Classifications

• B64G1/66

  Arrangements or adaptations of apparatus or instruments, not otherwise provided for · CPC title

• B64G1/22 Primary

  Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles · CPC title

• B64G1/36

  using sensors, e.g. sun-sensors, horizon sensors · CPC title

• B64G1/1021

  Earth observation satellites · CPC title

• B64G1/52

  Protection, safety or emergency devices; Survival aids · CPC title