Light sensor module, focused light sensor array, and an air vehicle so equipped

• US 7,397,019 B1
• Filed: 10/19/2005
• Issued: 07/08/2008
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Kissel, Stephen Joseph, Byars, James E., Ringdahl, John J.
• Primary Examiner(s): Epps; Georgia
• Assistant Examiner(s): YAM, STEPHEN K
• Application Number:
  US11/163,446
• Time in Patent Office: 993 Days
• Field of Search: 2502061-2063, 356 501- 508
• US Class Current: 250/206.1
• CPC Class Codes: F41G 7/226 Semi-active homing systems, i.e. comprising a receiver and involving auxiliary illuminating means, e.g. using auxiliary guiding missiles
• CPC Class Codes: F41G 7/2293 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 3/784 using a mosaic of detectors

Abstract

A light-sensing module and arrays of two or more light-sensing modules are described. Each light-sensing module comprises a mounting support structure that may include an air vehicle guidance section and an optical element adapted to direct incident light to a detector array that comprises an array of photodiodes and is attached to the mounting support structure. The detector array is adapted to receive the directed light and convert the received light to a set of electrical pulses via a plurality of photodetectors each of which is operatively coupled to an amplifier and a threshold circuit adapted to output a detection to a memory store adapted to associate a detection with a time-of-arrival. The light-sensing module may be adapted to output the associated detection and time-of-arrival. Air vehicles including the light-sensing modules are also disclosed.

Claims

1. An array comprising a plurality of light-sensing modules, each light-sensinglight-sensing module spaced apart from one another, wherein each light-sensinglight-sensing module has a field-of-view overlapping a portion of a field-of-view of at least one other light-sensing module of the plurality of light-sensing modules and wherein each light-sensing module comprises:

an optical element adapted to direct incident light to a detector array;

wherein the detector array is adapted to receive directed incident light and convert received light to a set of electrical pulses via a plurality of photodetectors, each photodetector operatively coupled to an amplifier and a threshold circuit, wherein each threshold circuit is adapted to output a detection signal to a first memory cell of a first memory store;

wherein the first memory store is adapted to associate the detection signal with a time tag; and

wherein the array further comprises a processing module adapted to correlate a first stored detection signal and an associated first time tag from a first light-sensing module of the plurality of light-sensing modules with a second stored detection signal and an associated second time tag from a second light-sensing module of the plurality of light-sensing modules.

2. The array of claim 1, wherein each photodetector is associated with a pixel location, each detection output signal is associated with a pixel location and the first memory store is further adapted to associate each detection signal with the associated pixel location.

3. The array of claim 1, wherein each photodetector is associated with a pixel location, each detection output signal is associated with a pixel location and the array further comprises a second memory store adapted to associate each detection signal with the associated pixel location.

4. The array of claim 1, wherein the optical element of at least one of the plurality of light-sensing modules is aligned with the detector array of the at least one of the plurality of light-sensing modules via an optical bench element.

5. The array of claim 1, wherein the optical element of at least one of the plurality of light-sensing modules is an aspheric, off-axis mirror.

6. The array of claim 1, wherein the plurality of light-sensing modules comprising the array are disposed in an annular array.

7. The array of claim 6, wherein the annular array comprising the plurality of light-sensing modules is a rotating annular array of light-sensing modules, wherein each light-sensing module is adapted to receive and output one or more detections of pulsed coherent light.

8. The air vehicle of claim 1, wherein the plurality of light-sensing modules of the array are disposed about an outer portion of a mounting structure.

9. An air vehicle comprising:

a fuselage and a guidance section comprising;

an array comprising a plurality of light-sensing modules, each light-sensing module spaced apart from one another, wherein each light-sensing module has a field-of-view overlapping a portion of a field-of-view of at least one other light-sensing module of the plurality of light-sensing modules and wherein each light-sensing module comprises;

an optical element adapted to direct incident light to a detector array;

wherein the detector array is adapted to receive directed incident light and convert received light to a set of electrical pulses via a plurality of photodetectors, each photodetector operatively coupled to an amplifier and a threshold circuit, wherein each threshold circuit is adapted to output a detection signal to a first memory cell of a first memory store;

wherein the first memory store is adapted to associate the detection signal with a time tag; and

wherein the array further comprises a processing module adapted to correlate a first stored detection signal and an associated first time tag from a first light-sensing module of the plurality of light-sensing modules with a second stored detection signal and an associated second time tag from a second light-sensing module of the plurality of light-sensing modules.

10. The air vehicle of claim 9, wherein each photodetector is associated with a pixel location, each detection output signal is associated with a pixel location and the first memory store is further adapted to associate each detection signal with the associated pixel location.

11. The air vehicle of claim 9, wherein each photodetector is associated with a pixel location, each detection output signal is associated with a pixel location and the array further comprises a second memory store adapted to associate each detection signal with the associated pixel location.

12. The air vehicle of claim 9, wherein the optical element of at least one of the plurality of light-sensing modules is aligned with the detector array of the at least one of the plurality of light-sensing modules via an optical bench element.

13. The air vehicle of claim 9, wherein the optical element is an aspheric, off-axis mirror.

14. The air vehicle of claim 9, wherein the plurality of light-sensing modules comprising the array are disposed in an annular array.

15. The air vehicle of claim 14, wherein the annular array comprising the plurality of light-sensing modules is a rotating annular array of light-sensing modules, wherein each light-sensing module is adapted to receive and output one or more detections of pulsed coherent light.

16. The air vehicle of claim 9, wherein the guidance section further comprises a signal processing module adapted to receive, from at least one of the plurality of light-sensing modules, one or more detections, each detection having a pixel location with an associated time tag and further adapted to correlate the pixel location and the time tag of each of the one or more detections.

17. The air vehicle of claim 9, wherein the plurality of light-sensing modules of the array are circumferentially disposed about the fuselage of the air vehicle.

18. A method of integrating a plurality of detections of a plurality of light pulses by a plurality of light-sensing modules, each light-sensing module spaced apart from one another, wherein each light-sensing module has a field-of-view overlapping a portion of a field-of-view of at least one other light-sensing module of the plurality of light-sensing modules and wherein each light-sensing module comprises an optical element, a photodetector array, and a front-end processing module, the method comprising the acts of:

for at least one of the plurality of light-sensing modules;

focusing at least one of a plurality of light pulses by an optical element onto a photodetector array to generate one or more detection signals, each detection signal from one or more photodetectors of the array;

amplifying and thresholding the generated one or more detection signals;

for each of the one or more detection signals;

storing each detection signal, with a time tag associated with a time-of-measurement of the detection signal, in a store location, wherein the store location is associated with the photo-detector array from which the detection signal was generated; and

extracting at least one of the stored detection signals from each of at least two of the plurality of light-sensing modules; and

correlating each of the extracted detection signals from the at least two of the plurality of light-sensing modules according to the store location and the time tag.