OPTICAL GUIDANCE SYSTEMS AND METHODS USING MUTUALLY DISTINCT SIGNAL-MODIFYING SENSORS

• US 20140204360A1
• Filed: 01/28/2014
• Published: 07/24/2014
• Est. Priority Date: 01/03/2012
• Status: Active Grant

• Current Assignee: Ascentia Imaging, Inc.
• Original Assignee: Ascentia Imaging, Inc.
• Inventors: Dowski, Edward R. Jr., Johnson, Gregory
• Granted Patent: US 9,739,864 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 1/70 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/74 Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G05D 1/101 specially adapted for aircraft
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones

Abstract

In an embodiment, a guidance system determines a location parameter of an object, and includes: at least one oscillating element located at the object for emitting modulated optical radiation; at least two mutually distinct signal-modifying electro-optical sensors, each of the electro-optical sensors having a detector and a demodulator for generating a demodulated electrical signal in response to detection of at least a portion of the modulated optical radiation; and a processor for determining the location parameter from the demodulated electrical signals. In another embodiment, a guidance system has aberration-corrected imaging and includes: a plurality of electro-optical sensors sharing a field of view and mutually distinctly providing a respective plurality of altered images therefrom; and an image generator module for linearly and non-linearly processing spatial frequency properties of the plurality of altered images to synthesize an aberration-corrected image for the imaging system.

Claims

1. Guidance system for determining a location parameter of an object, comprising:

at least one oscillating element located at the object for emitting modulated optical radiation;

at least two mutually distinct signal-modifying electro-optical sensors, each of the electro-optical sensors having a detector, and a demodulator for generating a demodulated electrical signal in response to detection of at least a portion of the modulated optical radiation;

a processor for determining the location parameter from the demodulated electrical signals.

2. Guidance system of claim 1, the at least one oscillating element comprising three transmitters emitting mutually distinctly modulated optical radiation, and the location parameter being three-dimensional location and three-dimensional orientation of the object relative to the electro-optical sensors.

3. Guidance system of claim 2, the demodulator being associated with a respective one of the at least three electro-optical sensors, each of the demodulated electrical signals being associated with an associated modulated optical radiation.

4. Guidance system of claim 3, the at least one transmitter being configured such that the modulated optical radiation is distinct from other electromagnetic radiation incident on the electro-optical sensors.

5. Guidance system of claim 1, the at least one detector comprising a single-pixel photodetector for detecting the modulated optical radiation.

6. Guidance system of claim 1, each demodulator further comprising a filter for rejecting higher-frequency components of the demodulated electrical signal.

7. Guidance system of claim 1, each demodulator acting to remove the effect of unwanted modulated or unmodulated signals

8. Guidance system of claim 1, the modulated optical radiation comprising a plurality of modulation frequencies for determining the object parameter with a respective plurality of accuracies.

9. Guidance system of claim 1, the modulated optical radiation comprising a plurality of modulation frequencies in order to estimate range through temporal processing and estimate angle through mutually distinct signal modifying sensors.

10. Guidance system of claim 1, the modulated optical radiation comprising a plurality of modulation frequencies in order to reject signals due to reflections.

11. Guidance system of claim 1, wherein each of the at least one oscillating element is a retro-reflector, the system further comprising a transmitter for transmitting the modulated optical radiation to the retro-reflector, for reflecting to the electro-optical sensors.

12. Guidance system of claim 11, the transmitter being configured such that the modulated optical radiation is distinct from other electromagnetic radiation incident on the electro-optic sensors.

13. Guidance system of claim 1, the modulated optical radiation having modulation frequency in the radio-frequency range.

14. Guidance system of claim 1, the modulated optical radiation having modulation frequency greater than 300 GHz.

15. Guidance system of claim 1, wherein the electro-optical sensors are mutually-distinct by imposing a mutually-distinct spatially-dependent modification on the incident optical radiation.

16. Guidance system of claim 15 wherein a phase plate with a spatially varying phase transmission function in imposes the mutually-distinct spatially-dependent modification on the incident optical radiation.

17. Guidance system with aberration-corrected imaging, comprising:

a plurality of electro-optical sensors sharing a field of view and mutually distinctly providing a respective plurality of altered images therefrom; and

an image generator module for linearly and non-linearly processing spatial frequency properties of the plurality of altered images to synthesize an aberration-corrected image for the imaging system.

18. Guidance system of claim 17, wherein intervening medium between an object in the shared field of view and the plurality of electro-optical sensors produces aberrations corrected by the imaging system.

19. Guidance system of claim 17, the plurality of electro-optical sensors comprising a respective plurality of mutually distinct signal-modifying optical elements for spatially modifying phase of incident optical radiation.

20. Guidance system of claim 19, each electro-optical sensor comprising an image sensor and an imaging objective for forming an image thereon, the imaging objective comprising the signal-modifying element.

21. Guidance system of claim 19, each electro-optical sensor comprising an image sensor and an imaging objective for forming an image thereon, the signal-modifying element being separate from the imaging objective.

22. Guidance system of claim 17, the image generator module comprising:

a synthesizing module for synthesizing a plurality of complex spatial frequency domain representations, each of the complex spatial frequency domain representations being a complex spatial frequency domain representation of a respective one of the plurality of altered images, to determine a composite modulation transfer function response and a composite phase response; and

a transformation module for combining and transforming the composite modulation transfer function and the composite phase response to generate the aberration-corrected image.

23. Guidance system of claim 22, the synthesizing module determining the composite modulation transfer function response from root-mean-square magnitude of the plurality of complex spatial frequency domain representations.

24. Guidance system of claim 22, the synthesizing module determining the composite phase response from weighted averaging of phases of the plurality of complex spatial frequency domain representations.

25. Guidance system of claim 24, the plurality of electro-optical sensors comprising a respective plurality of mutually distinct signal-modifying optical element for spatially modifying phase of incident optical radiation, and wherein weights in the weighted averaging are determined from phases of the plurality of signal-modifying optical elements.

26. Guidance system of claim 22, the transformation module further applying a normalization factor such that the composite modulation transfer function response best matches a reference modulation transfer function response.

27. Guidance system of claim 22, the image generator module comprising:

a processor;

a memory communicatively coupled with the processor, the memory comprising a non-volatile portion that includes (a) machine-readable synthesizing instructions that, when executed by the processor, perform the function of synthesizing, and (b) machine-readable transformation instructions that, when executed by the processor, perform the functions of combining and transforming.

28. Guidance system of claim 27, the machine-readable synthesizing instructions further including instructions for determining the composite modulation transfer function response from root-mean-square magnitude of the plurality of complex spatial frequency domain representations.

29. Guidance system of claim 27, the machine-readable synthesizing instructions further including instructions for determining the composite phase response from weighted averaging of phases of the plurality of complex spatial frequency domain representations.